The sum of the digits in a two digit number is 9. lf the digits are reversed, the new number will be 9 less than the original number. What is the original number?

1 Answer
P dilip_k
May 2, 2016

#54#

Explanation:

Since after reversal of position s of digits of the two digit numberthe new number formed is 9 less,the orinal number's 10's place digit is greater than that of unit place.
Let the 10's place digit be x
then the unit's place digit will be =9-x (since their sum is 9)
So the original mumber =#10x+9-x=9x+9#
After reversal mew number becomes #10(9-x)+x=90-9x#

By the given condition
#9x+9-90+9x=9#
#=>18x=90#
#=>x=90/8=5#

So the original number#9x+9=9xx5+9=54#

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