Question

The sum of the digits of a a-digit number is 9. It the number formed by reversing its digits is at less than the original number, find the original muerber.

Answer 1

Answer:

Take two numbers as x and y

x+y=9=>y=9−x

10x+y=10y+x−9

10x+9−x=10(9−x)+x−9

10x+9−x=90−10x+x−9

10x+10x−x−x=90−9–9

20x−2x=72

18x=72

x=72/18

x=4

Now put value of x in x+y=9

y+4=9

y=5

Now the two number digit is 54 which adds up to 9

and reversal of this two number digit yields a number 45 which id 9 less than 54 which is an original number.

Hope it helps.