Question

A number of two digits exceeds 7 times the sum of its digits by 6. If 45 is subtracted from the number, the digits are interchanged. Find the number.

Answer 1

Answer:

First digit = x         Second digit = y

Given : 10x+y-6 = 7x+7y

            10x+y-45=10y+x

___________________

10x+y-6 = 7x+7y

3x-6 = 6y

x-2 = 2y

x = 2y+2

Substitute x=2y+2 in 10x+y-45=10y+x

      10(2y+2)+y-45 = 10y+2y+2

      21y-25 = 12y+2

         9y = 27

            y=3

      x = 2y+2 = 8

The number = 10x+y = 80+3 = 83