Question

The sum of the digits of a two digit number is 8. If its digits are reversed, the new number so formed is increased by 18. What is the number ?

Answer 1

Let us assume, x and y are the two digits of a two-digit number
Therefore, the two-digit number = 10x + y and reversed number = 10y + x

Given:
x + y = 8 -----------1

Also given:
10y + x = 10x + y + 18
9y - 9x = 18
y - x = 2 ----------2

Adding equation 1 and equation 2
2y  =10
y = 5

Therefore, x = 8 - y = 8 - 5 = 3

Therefore, the two-digit number = 10x + y = 10*3 + 5 = 35