A boy was asked to multiply a certain number by 25. He multiplied it by 52 but got his answer more than actual by 324. What is the number?

A 12

B 15

C 25

D 32

Correct Answer: Option A

Let , the number = x

Actual answer = 25x

The wrong answer = 52x

Now, 52x - 25x = 324

or , 27x = 324

or, x = 324/27 = 12

So, the number was 12.