Question

A number consists of two digits number.if the digits iterchange their places and the new number is added to the original number,then the number becomes two time of the original number.Find the number?

Answer 1

Let the ten's digit be x and unit's digit be y.

Then, number = 10x + y.

Number obtained by interchanging the digits = 10y + x.

∴ (10x + y) + (10y + x) = 11(x + y), which is divisible by 11.