7X2 is a three-digit number in which X is a missing digit. If the number is divisible by 6, the missing digit is -

Question: 7X2 is a three-digit number in which X is a missing digit. If the number is divisible by 6, the missing digit is-

Solution:
The given number is divisible by 6, so it would be divisible by 2 and 3. As the last digit is 2, whatever be the value of X, it would be divisible by 2.
Now, 7 + X + 2 = 9 + X, must be divisible by 3.
So, X = 3 makes the number divisible by 3, so 3 is the required digit.