SOLUTION: A swimming pool is supplied with water through two pipes. When both pipes are used, the pool can be filled in 4,8 hours. The larger pipe alone will fill the pool in 4 hours less

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Question 785262: A swimming pool is supplied with water through two pipes. When both pipes are used, the pool can be filled in 4,8 hours. The larger pipe alone will fill the pool in 4 hours less time than the smaller one. Find the time required for each pipe separately to fill the pool.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
One job is, "fill the pool". We want to use rates in units of jobs per hour.

Combined Pipes fill rate, 1%2F4.8 jobs per hour.

Small pipe rate, 1%2Fx jobs per hour.
Larger pipe rate, 1%2F%28x-4%29 jobs per hour.
These two must be well understood before continuing....

The fill rates for the two pipes open at same time are directly additive, so the equation for this is
highlight%281%2F%28x%29%2B1%2F%28x-4%29=1%2F4.8%29 and you just solve the equation for x, the time needed for the small pipe to fill the pool by itself.