Question

A 2 digit numberis 3 more than 4 times the sum of its digits if 18 is added to the number the digits are reversed find the number

Answer 1

Let us assume the digits be x and y

Then the two-digit number is 10x + y

Given 10x + y = 4(x + y) + 3

            10x + y = 4x + 4y + 3

             6x – 3y = 3

             2x – y = 1………………….1

Given 10x + y + 18 = 10y + x

Or           9y – 9x = 18

                y – x = 2

                y = x + 2 ---------------------2

Substitute the value of y in eqn 1

2x – x – 2 = 1

x = 3

Therefore, y = 3 + 2 = 5

The two-digit number is 10x + y = (10 * 3) + 5 = 35