Question

If x is a digit such that the number $\overline{18x71}$ is divisible by 3, find possible vaues of x.

• A. 1
• B. 4
• C. 2
• D. 0

Answer 1

Answer: (A), (B)

The correct options are
A

1

B

4

$\because$ The number $\overline{18x71}$ is divisible by 3
$\therefore$ The sum of digits will also be divisible by 3
$\Rightarrow$ 1+ 8 + x + 7 + x 1 is divisible by 3
$\Rightarrow$ 17 + x is divisible by 3
The sum is greater than 17, it can be 18, 21, 24, 27..............
$\therefore$ x can be 1( x + 17 = 18, x = 1)

$\therefore$ x can be 4( x + 17 = 21, x = 4)