The sum of a two digit number and the number obtained by reversing the order of its digits is 121, and the two digits differ by 3. Find the number.

Answer

47 or 74

Explanation

Let the ten's digit be x and the unit's digit by y.
Then, `(10x + y) + (10y + x ) = 121 rArr 11(x + y ) = 121 rArr x + y = 11`
(x + y = 11, x - y = 3) or (x + y = 11, y - x = 3)`.