Question

A number consists of two digits whose sum is 10.If 18 is subtracted from the number,its digits are reversed.Find the number.

Answer 1

Let us assume, x and y are the two digits of the two-digit number

Therefore, the two-digit number = 10x + y and reversed number = 10y + x

Given:

x + y = 10 -------------1

also given:

10x + y - 18 = 10y + x
9x - 9y = 18
x - y = 2. -------------2

Adding equation 1 and equation 2

2x = 12
x = 6

Therefore, y = 10 - x = 10 - 6 = 4

The two-digit number = 10x + y = 10*6 + 4 = 64