Question

The sum of the digits of a two-digit number is eleven. If the digits are reversed, the new number is sixty-three less than the original number. Find the original number.


Help? &explain how you got the answer please.

Answer 1

let the unit digit be x, and the tens digit be y
then the origianl number is 10y+x

and the number reversed would be 10x + y

10x + y = 10y+x - 63
9x - 9y = -63
x - y = -7
but we also know x+y = 11
add them
2x = 4
x = 2 , then y = 9

the original number was 92

check
old number = 92
new number = 29
is 29 less than 92 by 63 ? YES!!!