Question

The sum of the digits of a two-digit number is 7. If the number formed by reversing the digits is less than the original number by 27, the original number is ___ .

• A. 43
• B. 61
• C. 52
• D. 25

Answer 1

The correct option is C

52

Let the units digit of the original number be x.

Then the tens digit of the original number is 7 - x

Then the number formed = 10(7 - x) + x × 1

Original number is 70 - 10x + x = 70 - 9x

On reversing the number=10x + (7-x) = 9x +7

New number = original number - 27

9x + 7 = 70 - 9x - 27

18x = 36

x = 2

The tens digit = 7 - 2 = 5

The original number is 52.