Question

a number consists of two digits whose sum is 9 .if 9 is subtractd from the number, it's digits are interchanged. find the number

Answer 1

let sums which form 9
1+8=9
2+7=9
3+6=9
4+5=9
5+4=9
6+3=9
7+2=9
8+1=9


now take all numbers and try you will get 54-9=45
there fore answer is 54