Question

The ones digit of a 2-digit number is twice the ten digit.When the number formed by reversing the digits is added to original number,the sum is 99.Find the original number.

Answer 1

let the no be 10x+y
y=2x
reverse no
10y+x

10x+y+10y+x=99
11x+11y=99
11x+22x=99

33x=99
x=3
original no is 36