Question

2. In a two digit number. The units digit is thrice the tens digit. If 36 is added to the number, the digits interchange their place. Find the number.​

Answer 1

Let the digit in the units place is x

And the digit in the tens place bey.

Then x 3y and the number 10y +x

The number obtained by reversing the digits is 10x+y.

If 36 is added to the number, digits interchange their places,

Therefore, we have 10y + X+ 36 = 10x +y

or, 10y-y +X+ 36 = 10x + y -y

or, 9y +X- 10x + 36 = 10x - 1OX

or, 9y - 9x+36 0 or, 9x - 9y = 36

or, 9(x - y) = 36

or, 9(x - y)/9 = 36/9

or, x- y =4. ()

Substituting the value of x = 3y in equation (), we get

3y-y 4

or, 2y 4

or, y = 4//2

or, y = 2

Substituting the value of y = 2 in equation (i), we get

x-2 4

or, x = 4+2

or, x = 6

Therefore, the number becomes 26.