SOLUTION: One pipe can fill a tank in 5 hours less than another. Together they can fill the tank in 5 hours. How long would it take each alone to fill the tank? Compute the answer to two dec

Algebra ->  Decimal-numbers -> SOLUTION: One pipe can fill a tank in 5 hours less than another. Together they can fill the tank in 5 hours. How long would it take each alone to fill the tank? Compute the answer to two dec      Log On


   

Question 1113669: One pipe can fill a tank in 5 hours less than another. Together they can fill the tank in 5 hours. How long would it take each alone to fill the tank? Compute the answer to two decimal places.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
FastPipe%2BSlowPipe=BothPipesTogether

1%2Fx%2B1%2F%28x%2B5%29=1%2F5

LCD 5x%28x%2B5%29

5%28x%2B5%29%2B5x=x%28x%2B5%29
5x%2B25%2B5x=x%5E2%2B5x
5x%2B25=x%5E2
x%5E2-5x-25=0
x=%285%2B-+sqrt%2825-4%28-25%29%29%29%2F2
x=%285%2B-+sqrt%28125%29%29%2F2
x=%285%2B5%2Asqrt%285%29%29%2F2
x=8.090

Ignoring the small fraction part of x,
The fast pipe would take 8 hours and the slow pipe would take 13 hours.