All solutions here are SUGGESTED. KS will hold no liability for any errors. Comments are entirely personal opinions.

Numerical Answers (click the questions for workings/explanation)

Question 1:

Question 2:

Question 3:

Question 4:

Question 5:

Question 6:

Question 7:

Question 8:

Question 9:

Question 10:

let depth of water be cm.

When

Comments/Explanations: This is easy. Just don’t make careless mistake with the .

(ai)

(aii)

.

(b)

Comments/Explanations: The integration by parts can be really tedious. so just be careful. As for the part, it can be both -1 or 1, depending on what n is. So we have two values of a.

(i)

(ii)

(iii)

Equation of Normal:

At E,

At F,

Area

Comments/ Explanations:

(a)

(i)

Note: Half line do not cut the center of the circle!

(ii)

Equation of Circle:

Equation of Bisector:

Solving, and

(b)

(ii)

For is purely imaginary and positive (lies on positive imaginary axis)

For to be imaginary,

For to be positive,

Comments/ Explanations:

(i)

Required probability

(ii)

Required probability

(iii)

Required probability

Comments/ Explanations:

(i)

(a)

Required answer

(b)

Required answer

(ii)

The sample collected will be representative of the employee’s gender and department, instead of their age. Thus, it will not be suitable as it is not representative.

(iii)

Let be the age of employees.

Let be the population mean age of employees

Under approximately by Central Limit Theorem.

Since is rejected,

(iv)

For to be not rejected,

Comments/Explanations:

(i)

Number of ways

(ii)

Number of ways

(iii)

Required Probability

(iv)

Required Probability

Comments/ Explanation:

(i)

[graph to be inserted]

is the outlier.

(ii)

The scatter diagram shows a curvilinear relationship between x and y variables. Thus, a linear model is not appropriate.

(iii)

d is positive since it represent the maximum efficiency obtained as the power increases.

c is negative since the scatter show an increasing trend.

(iv)

Using GC,

(v)

When

The estimate would be reliable since it is within the data range. The value is close to 1 which shows a strong linear relationship.

Comments/Explanations:

(i)

(b)

Using GC,

(c)

Let W denote the number of guesses that George made correctly, out all 100.

Since is large ,

approximately

by continuity correction

Comments/Explanations:

(i)

The mean number of a particular type of weed that grow on the field is a constant.

A particular type of weed growing on the field is independent of another particular type of weed growing on the field.

(ii)

Let X be the number of dandelion growing per .

(iii)

(iv)

Since approximately

by continuity correction

(v)

Let Y denote the number of daisies per .

Using GC,

Comments/ Explanation:

Q4 no need to find z1 z2

Yup, noted. cos was still solving a bit.

Hi , if i did not permute 3! for women in PnC qn 1st part , but used this value in my subsequent part , will there be ecf ?

Math have no ecf, unfortunately. You will still get method marks if you did explain what you were doing, in words

Hey I think the solutions section is linked to p1

because the same source code was used. so i’m just updating the solutions from there.

Hi there, if I didn’t find the probability for 7(iii) and 7(iv) but just the number of arrangements how many marks will I get? Thank you:)

just lose 1 mark for the answer mark. each.

If I took the wrong point for qn 8 is everything wrong?

even if i didn’t include 9! ? thank you:)

Why ur paper 2 answer is paper 1

because the same source code was used. so i’m just updating the solutions from there.

Aight, just realised. Thanks for your hardwork and effort!

Just wondering if anyone will do up the p3 for chemistry?

Nope, Eric is on vacation. Sorry

Hmm solution for q1 says 0.0251 but answer is 0.0252.. some discrepancy there

my bad. thanks for pointing it out!

Hi, I got 80 marks for Paper 1 and 63 for Paper 2. Guess my grade.

I mean 60 for paper 2 , 80 for paper 1

A

Based on the comments of your peers I think the bell curve ought to be pretty similar to that of last year so I’m afraid you’re at a borderline B. Don’t be discouraged though, work hard for your other papers!

Hi I think your question 8 c, d and y values are wrong

@mathmajor: I suspect you forgot to remove the anomalous point?

What are your values? I think you might have forgotten to remove the anomalous or removed the wrong data

I think I removed the point.. my y value was around 77.something. my r value was the same as his

if you keyed into GC, you probably forgot to key in as

Its correct

Isn’t the unit for Qn1 : m min-1?

my bad. cos rushing to solve the questions

Hi, thanks for the ans as usual. What mark range for combined p1+p2 would you suggest for an A grade? Thanks!

If I circled the wrong point, do i get method marks for the next few parts?

Im referring to question 8, sorry.

I dont think so, since there is no ECF.

For qn 8 can I reject x=2 instead of x=3

Hi, if I write in decimals for q5 will I still be rewarded marks?

yea, they didnt ask for exact

Good afternoon, for q4 can i use root 2 instead of 8 to 1/6 power? and for 2b can i leave it at 2nd last line except remove negative sign

thats fine

For question 6, for both sets of values, I wrote that they are subsets of R+, and then carelessly wrote that they are less than or equal to 0 for the lower limits. Would I lose the answer marks for both of these parts?

this? its okay.

Yup I wrote that! Oh kk! Thank you very much!

Hi what if igot 0.0250 for qns 1? How many marks will they deduct?

Hello, what do you think the cut off for an A would be, considering both papers? Thank you for posting the answers so quickly!

70+

Most likely 76+-2

How come 5 part 3 no need X6 for the number of cases?

i left it out accidentally while typing. but final answer no change.

For 6iii, if i wrote ans as x<34.8 but didnt write the 0<x part how many marks wil i lose?

one for the answer mark

What if for qn 7 (iii) and (iv) you did not realise that they are asking for probability? Then you just put the number of ways to arrange?

you lose 1m for the answer mark. each.

LOL thats what i did too! I weote 30240 for 7iii supposed to divide that by 9 factorial. But idk how do 7iv

All the answers look correct

77 for p1…67 for p2…any chance at all A or is even B too much to ask?

possible borderline A. Depending on your peers.

Whoa what jc are you from and do you usually score A for math in exams?

Im a private candidate! Scored A last year but no time study this year cause of NS. Retaking cause H2 icons i got U

good luck for econs on wednesday. suspect it will be novel

Thank you. Btw are you a fellow candidate?

Just asking, if i want to retake math, must i retake all my subjects for entry to uni?

Yes. Minimum 3H2 + GP for entry to local Uni.

Hi but what if i scored A for everthing excpt math and i wanna just retake math? Must i do all my subjects again the next year or just for math alone

sorry. But you can’t do that. For entry to local Uni, they look at the cert as a whole. You will need to retake at least 3H2 and GP. A cert with just h2 math as the single subject is useless, even with an A.

Question 5 iii) no nid to multiply by 6? Bc there are 6 cases of RBY,RYB,YBR,YRB…..

need. I forgot to typed it. but the final answer is still correct.

Hi, thank you so much for uploading the solutions. May I ask if we chose the wrong outlier in Q8, around how many marks will be lost?

7 (i) (ii) why do u need to multiply by 3! ?? the order women are chosen doesnt matter i thought?

they have different roles

For qn 8iv, if I removed the wrong point and used that value to calculate the c, d and r, are there any marks given?

How does KS find this paper?

The pure math was tedious. Finding for the complex requires student to use GC instead of drawing triangles, something I guess they aren’t used to. Finding the equation of bisector need them to realise it cuts the centre. Last part for complex is tricky as some might forget to check for the positive part. Stats is pretty okay. Sampling was a bit dubious with . PnC was easy but I reckon a handful of students did not see the word probability and paid 2 marks for that.

How did you find it?

i think many ways to solve the complex-tedious way can be you just find all the different equations and then calculate intersect

but good use of gc’s equation solver helped greatly (even for last question)-eqn solver is magical

overall slightly more novel (with the roulette style probability question) but manageable with all the hypo 0 tricks

But i thought it was slightly harder than previous years (since previous years it was almost all straightforward questions)

Omg yes I’m one of them. How many marks will be gone if never do probability but did the pnc only

you will just lose 1 mark for the answer. each

Omg thanks means I got chance to get 80 for paper 2!

Hi why can’t the outlier by x =5?

For 7 why does order matter? I thought is just how many ways to select the group of 3

but the 3 women can be different positions-chairperson/treasurer etc

but they didnt talk about their positions?

logically speaking its important

Why is the qn6iii and I’ve < I thought they wrote it is accepted so not rejected?

As in the question wrote accepted so I thought it meant that the answer is not rejected? Because my answer was in the opposite sign

It is a similar question in H1 this year. his claim is , to accept his claim, we need to reject and . Since

We need to be accepted, so has to be rejected.

Oh no do you think I would minus all the marks for that question?

some give you for defining terms and test statistics

Hais yeah i made the same mistake as you did 🙁

Do u think it’s possible to get an A if I got an Andrade of about 77? 🙁

I think should be fine. But it’s borderline. No careless then okay. 🙂 All the best for other papers

Hi, ‘KS Teng’, can u guess what is the min A grade? It’s okay to get this wrong 🙂 Not graded. To satisfy our curiosity

Got a 70 for Paper 1, 85 for Paper 2.. do you think it’s a safe A or will I drop to a B?

Omg what jc are you from and do you usally score A?

Hi, i only did the pure math part. Will i still get an A?

Why did you not do statistics?

50 for pure math, 100 for p1 thats 75 bro.

It’s 40 for pure math lol

I don’t think so unless your paper 1 u got full marks?

Thanks for the bell curve bruh

Hi KS! For qn 8 what if I circled x=5 instead of x=3? Do I lose marks for the entire question?

Then u will remove the wrong point and all your answers will be wrong. They will only minus answer mark.

so explanation marks will have? ;P

so explanation marks will have?

it depends how lenient they are. But i suspect since many people in singapore made this mistake, they wil adjust accordingly

for qn8 if we circle the wrong point, wil the explanation for ii and iii be awarded? it seems like it is independent of the point circled

the thing is that when you remove the wrong point, your answers for iii and v will be different :/ which point did you remove?

1st point ); but my c is negative and d is positive too. and the graph didnt follow the linear relationship as they stated

as in the part ii and iii where they ask u to explain but dont need to quote any values

How come it isn’t the first point which is the outlier? The first value is so off

IKR the first point was off

Assuming paper 1 I got 77 paper 2 I get 73 do I still have a chance u get A ?

Hi for qn 8 i didn’t remove the anomalous point for the calculations. How many marks will i lose

4 marks. I didnt too.

Thank you so much for the answers and the efforts, really appreciate that. Btw if I circled the point wrongly for the regression line question, will the whole question be wrong?

I believe the explanation can get marks. unfortunately, math has no ECF

ii and iii will have? but the rest wont be awarded?

But for c and d even though I circled the wrong point I still got the values correct, will that be wrong? Thanks!

Hi if I did not remove the anomalous point is everything wrong :9

For qn 8, if you accidentally removed the first point instead, do you still get credit for the remaining parts? And how come the first point is not the outlier? The first points is way too off

hi!! thank you so much for the answers and solutions! much appreciated 🙂

can i ask, if i forgot to exclude the outlier, does that mean there’ll be no ecf and thus 0 for the subsequent parts?TT_TT

the written answers still have marks.

Hi i forgot to exclude the outlier too, but since c,d,r are all based on GC answer, does that mean all 3 are wrong? And v will be wrong too?

Hi! For question 6(iii) and (iv), if the arrow is wrong, assume all else correct, how many marks would i be penalised, out of 7?

Hi for qn 8 if i didnt exclude the outliers will i only lose the answer mark for each part?

the mark for the questions goes too mostly the answer mark. for exp, your c, b, r will all be different

So 6 marks gone?

Hi i scored 107 overal do you think i can get a C?

Can anybody explain why isn’t the first value the outlier???

This is because the first point still follows the general trend. The equation of the curve is best suited to a y=c/x +d. An outlier doesnt follow the general trend of the curve, in this case a converging curve. Hence x=3 is most probable, although x=4 may be arguable as well.

What cause I thought the first value is the furthest away from the other values..

For question 4, you assumed the equation of the line bisector will pass through the center of the circle. Wouldn’t it be better if you had use the point of origin instead?

Thus y=-2.5x

If u drew the argand diagra right, the bisector passes through the centre of the circle, it doesn’t pass through the origin

The thing is u cannot just assume based on your drawing. What is confirmed is that the line will pass through (0,0)

It cant pass through the origin because the circle is on the right of the y axis and above the x axis and the bisector is downward sloping. I drew mine accurately using 2cm for every unit on the graph paper so it passed through the centre of the circle perfectly. If you’ve done many complex number qns, this is a technique required or else u wont be able to solve the question.

Yeah i misinterpreted the qn and used the equation of the circle and equation of line representing arg(z)=alpha 🙁

Oh nvm i misunderstood the question! Thanks!!!

The equation is a normal. Not tangent.

Hi, can i ask is the paper 2 tougher than paper 1? It seems that many did better for P1 than P2. Also, I got 70 for Paper 1 and 82 for Paper 2 so the average is 76. Is that still possible to achieve an A? Previously, you’ve mentioned that an A usually required 78 and above. Thanks! 🙂 and thanks for uploading the answers so promptly too!

Ya i think u will get an A. Do you always score A for math? Do you happen to be a fellow Rafflesian too ^^

I guess i will be the few rafflesians without an A 🙁 I got like 70 for both papers…

National distinction rate is about 50% though so don’t lose heart

If i got 67 for p1 and 63 for p2 can i still get a b?

Why isn’t the outlier x =5?

If we circled the wrong point is there ECF?

If I gt >55 for p2 and arnd 70 for p1, is it still possible to gt B? ._.

Hi For the complex no qn last part n=7 what if i misread qn for 2 smallest values and i say 1st n=7 and 2nd n=15? Any marks deducted? Thks!

What are your thoughts for this paper? What do you think the bellcurve will be like?

I made too many careless mistakes :'(

If I never draw the argument to scale will I lose marks for the entire question?

Hi KS just curious, what do you base your estimates for the min. number of marks to get A on? 🙂

Hi may I know the range of marks to get for a C?

@danielhuzil maybe you could get an A for icons if you learn to spell it 😛

Hi may I know is it possible to get C with 105/200? Thanks

Hello if I get 72 for paper 2 and 68 for paper 1 what grade will I get?

Probably an A

probably same grade as your name m8

Hi I circled the wrong outlier will my values for c,d and r be marked wrong???

Hi for Qn4, I carelessly wrote the arg for w as it’s conjugate. But the calculations were all right. Do you think the entire qn will be marked as wrong, including ii? Thank you so much for the answers btw!!

Pleasure. You will still get the method marks. Should lose about 2 marks though.

How many marks will I lose if I forgot to exclude outlier for parts (ii) to (v)? 🙁

prob 4 marks if u explained correctly

Hi, for questions 6, if my variance is wrong ( I went to find unbiased estimate) , how will it affect my marking for iii and iv?

You should still get marks for your hypotheses stated well, and method. Your answers will be wrong though and you will lose the answer marks

I believe the reason why the first point cannot be the outlier is because you will have problem explaining reliability later on (since you dont have a proper data range!)

Hi 🙂 will 130/200 guarantee a B?

That will. Good luck for the rest of your papers!

That’s true

Hi, is it ok if I give an exact answer for qn 1 and 4a2 thanks

Definitely. 🙂

Hi, for q8, removing x=1 will enable the |r| value to be closer to 1, so shouldn’t it be the answer? Thanks.

I think removing it causes the r value to worsen.

Hi Sir, is overall 75/76 safe for an A?😱

Safe as in guaranteed? Not really. You just have to see how the bell curve treats you.

How is hypothesis testing marked? Will I get 0 marks if I got H1 wrong from the start? As in I put > instead of <…

How is hypothesis testing marked? Will I get 0 marks if my H1 is wrong from the start?

The test in general has marks. But in this case, it’s really up to your presentation as there is no need to use any test statistic (no fault in stating though).

I got around 74 for paper 1 and 87 for p2. Do you think it is a safe A ?

Yup

Good job and all the best for your other papers!

How much do I need to get a C??

Hi KS may I ask why is the outlier not 1? It is really far off from the other points. Also will I be awarded any marks if all I did was draw a perpendicular bisector in 4ii?

Bisector got no marks. They didn’t give marks for finding them.

Outlier is at x=3, partly due to the last part of the question (this is some hint). The other reason is observed if you calculate the r value when you remove the point x=3 and x=1 respectively.

So the outlier is x=1 and not x=3?

It’s x=3

Hi if you remove x=1, then the answer would have been different from yours..

So is the outlier at x=1 or x=3?

for the PnC question if i forgot to multiply 3! for all the parts. will there be method marks if my methods are correct? thanks

If they see lenient, 1 mark. Cos this should be under the method mark too.

Hi why can’t x=5 be the outlier? And my answers were only arnd 0.02 different from urs for c,d and r so how many marks will I lose? Thank you for the answers btw!

Hi for your question 9c) working, you forgot to include 100 as the upper limit. (I.e. W is between 30 to 100 inclusive as there are only 100 questions). While the answer when rounded off will still be the same, since it is a 4 mark question, I think they might penalise for the missing working.

TBH, that’s fine. Cos when you approximate, the variance gets sufficiently small actually. 🙂

For qn 4, if I carelessly wrote |w| to be 8 instead of sqrt(8), and my cube roots are 2e^(i…) (the arg of the three cube roots are correct), do I lose all the marks for that part?

Can still get 1 mark for the method of and listing out all.

For 7i, if my ans is wrong. My ans is 4.then , for 7ii, if I write probability= No restriction -No men (same mistake)- 4. Do I get marks for 7ii?

I got 75/100 for paper 2 and 85/100 for paper 1.

Did negative marking tho… like if I got an ans wrong i’d deduct everything

Will I still get an A?

Seriously damn demoralised after today’s paper bc I heard A is quite high? 🙁

Definitely! All the best for the other papers!

I think u did damn well?! Why will you be worried. Your average is 80! And is even higher if you factor in method marks.

are you trying to rub it in or you simply cannot phantom that an average of 80 would give you an A that you need to confirm it?

I think she means no malice. It’s fine to have such concerns as there as a handful of students that find this paper more than manageable. Her concern is understandable 🙂

Yea rubbing it in and showing off

For the P and C question if i didnt find the probability and only found the no. of ways how many marks will I be deducted? I feel like Im too strict with myself. I deducted 4m out of 6m in my own working.

You lose 1 mark for the answer mark. Each

If u didn’t times three for 7(ii), how many marks will u lost? Thanks.

for question one, if I solve for dr/dt instead of dh/dt do I still have method mark or zero? If I have method marks how much would it be?

Hi I have about 85 for Paper 01 and 77 for Paper 02 (without method marks taken into consideration) based on your expected bell curve can I get my A?

Definitely! All the best for the rest of your papers!

So outlier as x=1 is correct?? But my values are different though.. Quite worried as might lose 6 marks worth due to that…

It’s x=3

Hi KS, i forgot to write ‘approx by CLT’ for the first part of HYPO testing… why i be mark down for tt?

this really depends on how you do the question. i didnt introduce Z test statistic at all, so I was using my distribution, thus there is a need to tell them how i derive my distribution.

If I got 74 for paper 1 and 63 for paper 2, do you think I can get A or will I even get B?

Sorry. But A will be really hard, unless you underestimated your score and got those numbers by not giving yourself method marks. B should be fine

Hi, thanks for the reply!

Is there any marks given for defining RV and u(in hypo)?

Also, I calculated mod r wronglying but my argument is correct for ques 4. Will I get 1 marry for it?

*wrongly

*mark

i dont think there is marks for the definition or rv and , since they didnt say define the variables you used. Its just presentation. you mean for writing w? its just writing, so i think thats 1 mark for getting it right. you probably have 0. but if your roots finding steps are correct, you can find 1 mark there.

Thanks Mr Teng!

Hi, if i got 71 for p1 and 62 for p2, will it be a guarantee B? Cause i heard this year’s math not many found it easy

Really depends on who you ask and where you ask. And yes, B should be fine

Overall 75 is A or B?

Hi just asking, what if for qns 1 my V forget to put pi but all working correct except final ans and the h (cause missing pi) how many marks lost

all working gone since you started out without pi

I think only the final parts I didn’t put the pi

Hi I got 84 for p1 68 for p2 will that be good enough for A? Thanks

I think might just be a bordering case of very high B or borderline A

Hello I think you integrated qn 2ai wrongly?? The 2nd term should be (2xcosnx)/n^-2??

In the solution with working

Noted! Thanks!

Yes. My bad. Typing error. Had to do by hand and type it out. Sorry bout it

Hi!! I would like to clarify if I can leave my answer for 2b as the one before your final answer. Thanks!

I think that shouldn’t be a problem

OMG, I just realised I forgot to exclude the outlier, may I know how many marks will I lose? Will they award method marks still for the following parts if my method used is correct?

there is no method marks there. just answer marks for c, d, r-value. unless you calculated them manually… you should get marks for the explanations

If I got 69 for p1 and 79 for p2 would I get an A or B?

Hi will I penalised if I used Z+ as the set notation instead of R for hypothesis testing?

yes. they mean very different things.

In that case is it safe to say that only the answer mark will be deducted from each part of the qn that requires R assuming everything else is correct?

yes

Okay thank you for the help

Yes, they are very different things

Hi, may i know what do you think the min marks will be for a B? I screwed up. 🙁 ~60 for p1 and 75 for p2

Hey there Mr Teng, for 1 and 2(b) i didn’t get the final answers but my methodology was exactly the same as you, would I still be awarded credit? Also, for my Correlation and Regression, I didn’t exclude the outlier before I calculated R, c and d, would I get 0 that 3 marks and the subsequent last part? Thanks for your constant efforts to provide timely answers! Cheers!

I think you will still get marks for methods, though it is hard to say how much as we do not know how much you’ve written or shown.

You’re supposed to remove the outlier, as stated in the questions, you might lose credit for the values of c, d and r-value. The same for the estimate, since all these are purely answer marks. You should get marks for your written explanations.

isn’t tan alpha = h/r for question 1?

the question said that

tan a is r/h not h/r…

Hi, can I ask for q6 last part does it matter if we exclude 8.68? Cos if p-value=significance level means null hypothesis still rejected.

Oso sry for bringing up a previous qn. For the complex no qn last part n=7 what if i misread qn for 2 smallest values and i say 1st n=7 and 2nd n=15? Any marks deducted?

Thks!

for question 6(iv), if you didn’t leave the alpha in terms of percentage, how many marks do u get? i left mine at 0.0868

might lose 2 marks.

Hi is it true that the national distinction rate is about 50% ? Doesn’t that mean that to get A you don’t really need a very high score?

Bell curve, I quote from Cambridge, is described as, “The grading for A/O levels is comparable to judging a student’s ability to swim 100 metres. If a student has evidently shown that he has been able to clear the 100 metres, that student will get the ‘A’ regardless of the number of people who are able to swim around the world.” So it is hard to say a very high score is need. H2 Physics is 40-45% distinction. O’levels E Math is also 50% distinction.

that being said, the cut off for A should maintain at 70, and not 77 as it has been suggested in the above thread

technically, if you put school distinction rate against national distinction rate, you will get a very different graph which suggest a very mean score. bell curve ensures students dont fail and the A deserve their A and Bs deserve their Bs.

I heard from my math teacher that the number of As awarded is predetermined by the examination board and that they are likely to award more As in mathematics and physics due to the lack of engineers in Singapore haha.

hi! i am a student from hci. guys please relax and jiayou for the papers ahead !! a lot of my peers and i in fact, found the paper quite tough tbh!! more difficult than the past year papers and this year’s paper 2 pure math was definitely more challenging 🙂 point is, there really isn’t any use in knowing where you stand/ whether you can get your a for math i guess. because no one knows how the entire cohort is going to fare right 🙂 let’s just jiayou and focus on the remaining papers!!! and continue to have faith!!!

But HCI even when they say it’s tedious a majority will score 80++ I’m pretty sure

You guys are just plain smart I matter how tough or time consuming you guys will still score very well 🙁

no la, theres just a large divide perhaps some people will consistently hit, while others don’t. Nobody is plain smart you can still make many careless mistakes.

Since top tier schools like hci, rI, vjc,njc… have majority (abt 80%) of their students get A for math, the rest of us need some assurance for grading lol.

Is 60 (average of both papers) a possible B? I had really bad time management for this paper ): thank you!

Same 🙁 for p2 i didnt do the last qn hais and it was so easy too….

Probably a C

How marks do you need to obtain a E grade?

If i got 40 for paper 1 and 60 for paper 2, will i be able to pass? I am so screwedd😭

I got E grade last year. I calculated avg 50% for both papers :/

Not v accurate to say that!! Dont lose hope.. moreover this paper seemed harder to everyone so hopefully it all turns out well!!

Well last year was apparently a “very tedious” paper as well compared to 2014 and below.

every year, students think theirs is the hardest. :/

Hi if i made a careless mistake in 1 by writing r=2h , subsequently everything is right (according to r=2h) except for ans mark will i lose everything???)-:

you might lose 2 marks. the method for the substitution too.

we can actually use complement for 7(iv)

Probability = 1 – {C, S, T together} – {any two of C, S, T together}

= 1 – \frac{1}{12} (from (iii)) – (3C2 x 2! x 7C2 x 2! x 6!)/9! = 1 – 1/12 – 1/2 = 5/12

yes, but this seems to be a lot more work!

Damn I tried doing this method but got stuck halfway and didn’t do this part!!

Hi is an 85 for paper 1 and 72 for paper 2 enough for an A

no point guessing. many things can happen during marking

Paper 1 if I get about 60 and paper 2 about 70, am i likely to get a B or A?

think thats a B. sorry. All the best for your other papers!

Hi! For Q6(iii) hypo testing, I carelessly thought that Ho is not rejected and I put >0.05, my final ans was >34.8, but my values and method are all the same as yours. How many marks will I lose? Thanks!

i think just lose 2 marks.

Hi Mr Teng, i got 74 for paper 1 and 75 for paper 2 do i have a chance of getting the A? Thanks 🙂

Hi, i think its thats a borderline. Either a high B or border A.

Would 173/200 get me an A?

Definitely. All the best for the rest of your papers!

Hi, if i got around 80 for both paper 1 and 2, how would I fare? Thank u so much for your answers btw!

i think if you got above 80 for average, you’re very safe. 🙂 and its my pleasure. all the best for your other papers!

For the complex qn (4aii) values of z I thought it was just the modulus so I gave the length only 🙁 how many marks would be deducted? Thank you 🙂

but they didnt ask for modulus at all. i think you might not get any marks.

Hi KS, may I ask if for question 2b, instead of du/dx, i went to find dx/du by making x the subject is that ok? However I made some careless mistake along the way I ended with [root(9-u)]/u^2) instead of your (9-u/u^2), how many marks will I receive for this question?

thats perfectly fine. you might end up with 1 – 2 marks.

Out of 5?

because your method for the integration is gone. unless somehow you integrated the correct expression. :/ Math has no ECF, as precision is one of the mathematical skills we look to test.

Hi Mr Teng, is it true that every year you are teaching Math, the national average distinction is roughly 50% without much fluctuations?

yes, for 9740 h2 math. its been roughly 50% national average. but i believe in statistics, and what’s truly reflective is the school distinction rate. it tells more.

hey i got 85 for paper 1 and about 81 for paper 2 ? are my chances of A gone since most people in those good schools will probably do very well.

definitely can get A. All the best for your other papers

do you know the national average for H2 math for 2015?

was about 51%

as in the score?

its 78/79, because i know a few borderline cases.

What do u think is min A? 74? 75? 76? 77? 78?

50% of the nation scores above 79??

I’m currently at 76 :< sigh so close yet so far

what’s the national passing rate?? pass is E grade right?

Hi, if I didn’t times three in 7(ii), how many marks will I lost out of the total three marks? ThaNs.

thanks for the all the advice on this website , appreciate it

If my scatter diagram the anomaly point I circle wrongly then behind got ecf or not ah?

Math got no ecf, you lose marks for R, D, C and circling the answer as well as the 1st part of last part. Abt 5 marks lost

For the scatter diagram i did not see the part that it needed to be drawn on graph paper, and drew it normally on the foolscap, but to scale. Will i get any marks?

Hi if i scored 107 overall is that a D or C?…will bell curve help?

No, cause they said graph paper

Hi if of excluded the correct outlier but I forgot to circle it on the graph (lol) will just minus 1 mark right coz for the next few parts my values are correct, and if I didn’t leave to 3 sf but 5 sf instead will there be another mark lost ?

If u didnt leave in 3sf then it will be wrong because the oaper expects it to be 3sf. You lose the answer marks

Yes, all non-exact answers to be in 3SF unless otherwise stated. Always tell my students to read the instructions carefully.

If i didnt use continuity correction how many marks will i lose

HOW DO YOU GUYS EVEN DARE TO CHECK THE ANSWERS? Aren’t you guys scared that if you find qns that you made mistakes in, you won’t be able to concentrate on other papers? I don’t understand how you guys do it

Because on the other hand when u realise ur answers are correct u will be more confident in aceing the others😊 And knowing that u are doomed will also motivate u to study harder for the others right and not becoming too complacent. Anyway all the best for the remaining papers!

Hi im around a 77-79% right now is it likely if i get an A?

yea should be likely

Hi Mr Teng, do you think Cambridge will accept x=5 outlier? Since the r value is actually 0.977, and the idea of correlation should allow for a notion of ‘best fit’, omitting x=5 actually still gives a 1/x trend. :/

I am also convinced that x=3 is the best candidate for a outlier, just curious as to is statistics so steadfast in forcing all data plots to fit a desired mathematical model. 🙂

Yes. that’s actually under regression analysis.

This is debatable i guess. But I’m sure I can give you a valid reason. Just that I haven’t got a chance to try x=5. :/

Omg i’m so so disappointed in myself because i can’t handle exam stress so my mind totally shut down during exam… my paper was pretty bad and i think i got around 75 for paper 1 and 60 for paper 2 bc i was so nervous argh. Will that give me a B thoooooo

I think you should get a B. Or maybe you were too harsh on yourself and minus all the method marks when you counted. don’t worry

All the best for your other papers!

How many marks will u lose if u circled the wrong point and forgot to leave out the anomalous point?

You lose the marks for c, d and r-value. You also lose the marks for the estimation of y. Also the circle part. So that should be 5. Your written explanation will be eligible for marks

Wad if my fren for ytd p2 qn 1 he did dvdr instead of dvdh? Will be minus everything? Cos his methods are all correct just that he screw up the variables

And is 74 for p2 and 84 for p1 safe?

I think it’s fine for A

All the best for the other papers!

That should be fine too actually. Since both r and h are variables, some of my students did implicit differentiation too. The final answer should be the same though.

But he tot r is h

For paper 2, q4(a)(ii), I got the equation of the circle and the equation of the normal, but then didn’t equate them… how many marks can I get?

for q4(b)(i), I got the modulus and argument of w, and I remembered to divide the argument by 3, but forgot to cube the modulus, how many marks can I get?

for q4(b)(ii) I managed to get to the step (n-1)arg(w) = 0.5pi. but i couldn’t solve for n, how many marks can i get?

For q8, I was super careless. I circled the 4th point in my graph, but then omitted the 3rd point in my workings…however, the value for d is the same as the ans (though my values of c and r) are wrong. Can I get 1 mark for my d value? and if i use these c and d values to get my answer for (v), will i be awarded the method mark at least?

for q10 (iv), I got 0.80045, then at first i rounded it off to 0.8005 (4sf), then i rounded it off to 0.801 (3sf) though the correct ans is 0.800… will I be penalised?

Many thanks for your patience 🙂 We all appreciate your input and help very very much

Hi KS just wondering if you saw my comment? 🙂

Hi, I’m sorry bout that. I clearly overlooked it.

P2Q4aii, with the equations, correctly found. You should get 2 marks

P2Q4bi, should be 1 mark max

P2Q4bii, should be 1 mark max

P2Q8, you should get 1 marks for the d if it’s correct. As for the (v), it’s only 1 mark for the answer, so you won’t get any.

P2Q10, yes the answer is wrong. You will lose the answer mark.

If I didn’t times three for 7(ii), how many marks will I lost? Thanks for answering.

For qn 5, how many marks will u lost if u didn’t times 3!?

For all the parts, you will get 1 mark for each parts I reckon cos it’s part of the methods necessary

Hi would saying the population size is too large for 6bii get me any marks? Also is 76/100 likely to be an A?

similar to the comment above, i did the wrong substitution for question 1 and calculated dr/dt instead of dh/dt, the answer i got was 0.0125 (exactly half). i am sure that i did the differentiation and subsequently calculation correctly. will i be awarded any marks at all?

For 4ii) do you still get method marks for finding Z1 Z2 instead? :/

It’s irrelevant though. Shouldn’t be a Margie part.

Hi, if I didn’t times three in 7(ii), how many marks will I lost out of the total three marks? Thanks for answering my question.

For that part? Might be 2 marks. Cos it’s needed for all the parts

Is 59 males correct for question 6

Should round up

i did the wrong substitution for question 1 and calculated dr/dt instead of dh/dt, the answer i got was 0.0125 (exactly half). i am sure that i did the differentiation and subsequently calculation correctly. will i be awarded any marks at all? sorry for reposting! 🙁

sorry, if i overlooked.you should get 3-4 marks for method

Hi if my inequalities for hypo testing I got more and equal to zero will I get the whole thing wrong? So minus 1 mark for each inequality? Thank you

your hypotheses are worth 1 mark. but given its wrong, your solving part, the inequality also wrong.

Why for 6iii, cannot write 0<x<34.8?

This is wrong for 6ii right? Each department can choose to hire all the younger workers or all the older workers.

Will I get any method marks if I wrote this ?

Qn 7i. No of ways= 4C3=24

Qn 7ii. No restriction= 10C3

No men=24

No women= 6C3

Total ways= 10C3-24-6C3

Will I get anything if I only wrote until the 4th line in ur 10v ans? After that , I made mistakes.

I doubt so. unless you expanded the probability equation.

you will get 0, 1 marks respectively for the parts

the question states it wants the answer as a set of values. your given answer is a range of values.

as in for my set of values instead of 0< i left it as more than and equals to zero. is that wrong? thank you so much 🙂

that is fine. i doubt they nitpick on this small detail. putting it is already good

hi,

For the explanation for the scatter plot, could I say c is negative to reflect the shape of the graph to fit the shape of thr scatter plot

And for d ti be positive, to translate the graph in the positive y direction to fit the positivevalue of y given.

Thanks

the explanation for c is fine. But i don’t see why we are doing any translation here.

Uhhhhg

Sorry did not mean to spam, hey for question 7a pnc, if I did not permutate my answers, will I get any method mark? Especially for the 3 mark one

You might just get 1 mark if all else if correct. 3! is part of the method

For the scatter plot, I said that c is negative since X values r inversed, hence y decreases as X increases

i know it’s supposed to be reciprocal, but I wrote inverse by accident >.< will I still get the mark? And is 76 + 82 sufficient for A?

Inverse and reciprocal have very different meanings. Awarding you the 1 mark will be based on whether the marker is lenient and like to try and understand what you’re saying.