Question

A two digit number has, sum of its digits half of its value.

Answer 1

Let the two digit number be xy.
Then sum of its digits = x+y
It's value=10x+y
As per question,
2(x+y)=10x+y
2x+2y=10x+y
2y-y=10x-2x
y=8x

Let assume x to be 1. Then y=(8×1)=8
The number=18.