Question

Pipes a and b can completely fill a water tank in 4 and 5 hours respectively. A pipe c can empty a tank filled

Answer 1

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Pipes A and B can fill the tank in 5 and 6 hours respectively. Therefore,
part filled by pipe A in 1 hour =15=15
part filled by pipe B in 1 hour = 1616

Pipe C can empty the tank in 12 hours. Therefore,
part emptied by pipe C in 1 hour =112=112

Net part filled by Pipes A,B,C together in 1 hour
=15+16−112=1760=15+16−112=1760

i.e., the tank can be filled in 60/17 hours.



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