Question

The sum of the two digit number is 9. The number obtained by reversing the digits is 9 less than the original number. Find the number.

Answer 1

Let us assume, the x and y are the two digits of a two-digit number
Therefore, the two-digit number = 10x + y and the reversed number = 10y + x
Given:
x + y = 9 --------1
Also given:
10y + x = 10x + y - 9
9x - 9y = 9
x - y = 1
Adding equation 1 and equation 2
2x = 10
x = 5
Therefore, y = 9 - x = 9 - 5 = 4
Therefore, the two-digit number = 10x + y = (10 * 5) + 4 = 54