Question

The ratio of a two-digit natural number to a number formed by reversing its digits is 13: 31. The number of such pairs is:

• A. 1
• B. 2
• C. 3
• D. More than 3

Answer 1

The correct option is C 3

Let the two digit number = ab → 10a+b
By reversing, ba → 10b+a
Now ab: ba = 13: 31
So, 31(10a+b) = 13(10b+a) → a: b = 1: 3
Possible numbers are 13, 26, and 39.