The sum of the digits of a two digit number is 6.If 18 is subtracted from the number, the digits in the number are interchanged . Find the number.

Answer 1

unit digit ---- x
tens digit --- y
so the number is 10y + x

10y + x - 18 = 10x + y
9y - 9x = 18
y - x = 2
also: x+y=6
add those last two equation:
2y = 8
y = 4
so x = 2

the number is 42

check:
is 42 - 18 = 24 ? YES

Answer 2

yes