Question

Sum of the digits of $2$ - digit number is $8$. If $18$ is added to the number, the digits change their places. Find the number.

Answer 1

Let the number be x and a be at tens place and b be at ones place

$x=10a+ba+b=8$

$10a+b+18=10b+a$

$b-a=2$

$b=5$

$a=3$

$x=35$