Question

The sum of digit of a 2 digit number is 15. The number obtained by reversing the order of its digits of the given number excides the given number by 9. Find the given number

Answer 1

Let the digits be x and y

Therefore

the two digit number = 10x + y

According to Question,

x + y = 15 ----------> (1)

And

10y+x = 10x+y +9

=> 10y - y +x -10x = 9

=> 9y - 9x=9

=>9 ( y - x) = 9

=> y - x = 1 ---------->( 2)

Adding (1) and (2) we have ,

=> x + y + y - x = 15+1

=> 2y = 16

=> y = 8

Again from (2) ,

8 - x = 1

=> -x = 1-8

=> -x = -7

=>x = 7

Therefore required number is

10×7+8

=70+8

=78