Question

pipes A and B can fill an empty tank in 8 hours and 12 hours respectively. if both the pipes are opened together, how many hours will it take to fill the empty tank?​

Answer 1

Step-by-step explanation:

Pipe A fills an empty tank in 12 hour

So pipe A fills a fraction 1/12 of the whole in one hour.

Similarly Pipe B fills a fraction 1/15 of the whole in one hour.

In one hour the fraction of the whole tank is filled when both pipes A and B are opened together = 1/12 + 1/15 = 5/60 + 4/60 = 9/60

The time taken to fill the empty tank completely when both pipes A and B are opened togetger = 60/9 hour = 6 hour 40 minute.