Question

two taps A and B can together fill a swimming pool in 15 days the taps A and B are kept open for 12 days and then the tap B is closed it took another 8 days for a tap to fill the pool. how many days does each tap required to fill the pool

Answer 1

Let A and B be the rates of the 2 taps.15A + 15B = 1 job20A + 12B = 1 jobMultiply through the top equation by 12multiply through the bottom equation by 15180A + 180B = 12300A + 180B = 15Subtract and solve for A120A = 3A = 40A would take 40 days to fill the pool alone.Solve for "B"20A + 12B = 11/2 + 12B = 112B = 1/2B = 24B would take 24 days to fill the pool alone. 

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