Question

The sum of digits of a two digit number
is 15. The number obtained by interchanging the digits exceeds the given number by 9. Find the number

Answer 1

at_answer_text_math

One digit=x,another digit=15-x

Let x be the tens digit and 15-x is in ones digit.

actual no=10x+15-x=9x+15

When interchanged,=10(15-x)+x=150-10x+x=150-9x

ATQ

=>9x+15+9=150-9x

=>9x+9x=150-24

=>18x=126

=>x=126/18=7

The no.=9x7+15=63+15=78

Answer 2

As ten's digit×10 + one's digit =number