SOLUTION: A Chinese restaurant has a large goldfish pond. Suppose that an inlet pipe and a hose together can fill the pond in 7 hours. The inlet pipe alone can complete the job in one hour l

Algebra ->  Pythagorean-theorem -> SOLUTION: A Chinese restaurant has a large goldfish pond. Suppose that an inlet pipe and a hose together can fill the pond in 7 hours. The inlet pipe alone can complete the job in one hour l      Log On


   

Question 1091897: A Chinese restaurant has a large goldfish pond. Suppose that an inlet pipe and a hose together can fill the pond in 7 hours. The inlet pipe alone can complete the job in one hour less time than the hose alone. Find the time that the hose can complete the job alone.
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39623) About Me  (Show Source):
You can put this solution on YOUR website!
x, time for the hose alone

1%2F%28x-1%29%2B1%2Fx=1%2F7
-
7x%2B7%28x-1%29=x%28x-1%29
7x%2B7x-7=x%5E2-x
14x-7=x%5E2-x
x%5E2-15x%2B7=0

x=%2815%2B-+sqrt%28225-4%2A7%29%29%2F2
(only one alternative will be right.)
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Answer by ikleyn(52834) About Me  (Show Source):
You can put this solution on YOUR website!
.
The solution by @josgarithmetic 
    x=%2813%2Bsqrt%28197%29%29%2F2


    x=13.5178 hours
    or 13 hours 31 minutes

is highlight%28WRONG%29. The correct solution is 
    x = %2815%2Bsqrt%28197%29%29%2F2


    x = 14.5178 hours
    or 14 hours 31 minutes