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(i)
Required Probability
$= \frac{3 \times 4 \times 3 \times 2 \times 1}{5!}$

$= \frac{3}{5}$

(ii)
Required Probability
$= \frac{3 \times 2 \times 1 \times 2 \times 1}{5!}$

$= \frac{1}{10}$

(iii)
Case 1: The first digit is 3 or 5

$\frac{2 \times 3 \times 2 \times 1 \times 2}{5!}$

$= \frac{1}{5}$

Case 2: The first digit is 4

$\frac{1 \times 3 \times 2 \times 1 \times 3}{5!}$

$= \frac{3}{20}$

Required Probability $= \frac{1}{5} + \frac{3}{20} = \frac{7}{20}$