Question 196261: The tens digit is twice the units digit. The sum of the original number and the number represented when the digits are interchanged is 66. Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! The tens digit is twice the units digit. The sum of the original number and the number represented when the digits are interchanged is 66.
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Let the number be 10t + u ; t is the tens digit ; u is the units digit.
Equations:
t = 2u
10t+u + 10u+t = 66
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Simplify:
t = 2u
11t + 11u = 66
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Simplify:
t = 2u
t + u = 6
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Substitute:
2u + u = 6
3u = 6
u = 2 (units digit)
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substitute into t = 2u to get:
t = 2u = 2*2 = 4 (tens digit)
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Original Number:
10t + u = 42
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Cheers,
Stan H.
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