Question

the sum of the digits of a two digit number is 5.if 9 is added to the number,the digits are interchanged.find the number.

Answer 1

let the digits be x and 5-x
ATQ
(10x + 5-x ) + 9 = 10(5-x ) + x
9x + 14 = 50 - 10x + x
9x + 9x = 50-14
18x = 36
x = 2
the number is 23