Question

If 5x6 is exactly divisible by 3, then the least value of x is

(a) 0

(b) 1

(c) 2

(d) 3

Answer 1

$\because$ 5x6 is exactly divisible by 3

$\therefore$ Sum of its digits must be divisible by 3

$\therefore$ 5 + x + 6 = 11 + x is divisible by 3

$\therefore$ Least value of x = 1 as 12 is divisible by 3 (b)