Question

Alex was asked to multiply a number by 23. He instead multiplied the number by 32 and got the result 135 more than the correct answer. The number to be multiplied is _____ .

• A. 10
• B. 20
• C. 9
• D. 15

Answer 1

The correct option is D 15

Let's assume number to multiplies is $x$.

As given Alex was asked to multiply $x$ by 23. But he multiplied with 32.
So change in result will be,
$32\times x-23\times x=32x-23x=9x$

So, according to the question,
$9x=135x=\frac{135}{9}x=15$

Hence, option 'd' is correct.