All solutions here are SUGGESTED. Mr. Teng will hold no liability for any errors. Comments are entirely personal opinions.
Stratify the residents of the city suburb into different age groups.
Stand on a street corner and ask people who walk past until the required number of people in each age group have been interviewed.
The sample obtained is non-random as not every resident in the city suburb has an equal chance of being selected.
Not everyone that walks there is a resident.
It would not be realistic as we will not be able to obtain the sampling frome.
Most questions today require students to be able to answer in the required context. So students need to understand the sampling methods so as to phrase them appropriately.