On dividing a number by 357, we get 39 as remainder. On dividing the same number 17, what will be the remainder ?

Answer: Option C

Let x be the number and y be the quotient. Then,
x = 357 × y + 39
   = (17 × 21 × y) + (17 × 2) + 5
   = 17 × (21y + 2) + 5
∴ Required remainder = 5