Question

Tick (✓) the correct answer
If 7x8 is exactly divisible by 9, then the least value of x is
(a) 0
(b) 2
(c) 3
(d) 5

Answer 1

(c) 3

If a number is exactly divisible by 9, the sum of the digits must also be divisible by 9.
$7+x+8=15+x$
18 is divisible by 9.
∴ $15+x=18\Rightarrow x=3$