Question

Tick (✓) the correct answer
If 5x6 is exactly divisible by 3, then the least value of x is
(a) 0
(b) 1
(c) 2
(d) 3

Answer 1

(b) 1

If a number is exactly divisible by 3, the sum of the digits must also be divisible by 3.
$5+x+6=11+x$ must be divisible by 3.
The smallest value of $x$ is 1.
$x=1$
$\Rightarrow x+11=12$ is divisible by 3.