Question

The sum of the digits of a 2- digit number is 11 . The number obtained by interchanging the digits exceeds by 27 . Find the number.

Answer 1

let tens digit =t

let units digit =u

t+u=11

u=11−t

10u+t=10t+u+27

10(11−t)+t=10t+(11−t)+27

110−9t=9t+38

9t=72−9t

18t=72

t=4

u=11-4=7

tu=47

Interchanging the numbers , we get

ut=74

Verify:

4+7=11

47+27=74