Question

the digits of a two digit number differ by 7 if the digits are interchanged and the resulting number is added to the original number we get 121 find the original number

Answer 1

hi

let the number be xy

tens place = 10x

ones place = y

The digits of a two digit number differ by 7

x - y = 7.....[1]

if the digits are interchanged and the resulting number is added to the original number we get 121

so,

10y + x + 10x +y = 121

11x +11y = 121

now,

x + y = 11.....[2]

now , [1] and [2]  since

x  - y = 7 

x +y = 11

on adding them

2x = 18

x = 9

now y = x - 7

= 9 -7

=2

hence the original number is xy

= 92

hope it helps u

:) 

Answer 2

hope this answer will help you