Question

The sum of the digits of a two digit number is 7. On reversing the digits, the
new number obtained is 9 more than the original number. Find the number.
​

Answer 1

let the unit place digit be x

and tens place digit be 15-x

original no.=150-10x+x=150-9x

by reversing digits

new no.=10x +15-x=9x+15

According to question,

9x+15-(250-9x)=9

9x+15-150-9x=9

18x=144

x=144/18

x=8