Question 415587
A filler pipe can fill a tank in 10 hours, while an outlet pipe can empty the tank in 15 hours. How long will it take to fill the empty tank with both pipes operating?
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Equation:
rate - rate = together rate
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I have tried 
1/10 - 1/15 = 1/t
Multiply thru by 150t to get:
15t - 10t = 150
5t = 150
t = 30 hrs.
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Cheers,
Stan H.
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