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

Let x be the number and y be the quotient. Then,

x = 357 x y + 39

  = (17 x 21 x y) + (17 x 2) + 5

  = 17 x (21y + 2) + 5)

Required remainder = 5.