Question

sum of a two digit number is 8. If the number obtained on interchanging the digit is 36 more than the original number. find the number

Answer 1

let the digits be x and y
$x + y = 8 \\ y = 8 - x \\ 10y + x = 10x + y + 36 \\ 9y - 9x = 36 \\y - x = 4 \\ 8 - x - x = 4 \\ 2x = 4 \\ x = 2 \\ y = 8 - 2 \\ y = 6 \\ the \: digit \: is \: 26$