Question

The difference between a two-digit number and the number obtained by interchanging the digits is 36. What is the difference between the sum and the difference of the digits of the number if the ratio between the digits of the number is 1 : 2 ?

Answer 1

let the tens digit be x and unit digit be y
then
10x+y-10y-x=36
9x-9y=36
x-y=4 -----------------------------------------------------------1
now
x=2y
now putting this value of x in 1
2y-y=4
y=4
therefor x=8
then number is 84
now

sum of digits=12 and difference of digits is 4

12-4=8------------------------------------------------------------ans