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Question 117720: When the digits of a two-digit number are reversed, the new number is 9 more than the original number, and the sum of the digits of the original number is 11. What is the original number?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! When the digits of a two-digit number are reversed, the new number is 9 more than the original number, and the sum of the digits of the original number is 11. What is the original number?
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Let the original number be 10t+u where t is the tens digit and u is the units
digit.
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When reversed the number would be 10u+t
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EQUATION:
10u+t=10t+u+9
t+u=11
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Rearrange to get:
9u-9t=9
u-t=1
u+t=11
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Add the last two to solve for "u":
2u = 12
u = 6
Substitute to solve for "t":
6+t=11
t = 5
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Original Number: 56
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Cheers,
Stan H.
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