Question

Two pipes fill a cistern in 4 and 6 hours.If both the pipes are opened together how many hours will it take to fill the tank

Answer 1

Answer:

Let the capacity of tank = Lcm (6,4) = 12 liters

Pipe A will fill 12/6 = 2 liters per hr

Pipe B will fill 12/4 = 3 liters per hr

If A is opened first for 1 hour and then B is opened for 1 hour, they will fill 5 liters in 2 hrs

Number of such cycles = [12/5] = 2 or 4 hrs

Remaining 2 liters will be filled by A in 1 hr

:. Total time taken = 4 + 1 = 5 hours.

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