Question

Two pipes can separately fill a tank in 20 and 30 hours respectively. Both the pipes are opened to fill the tank but when the tank is full, a leak develops in the tank through which one-third of water supplied by both the pipes goes out. What is the total time taken to fill the tank?

Answer 1

Answer:

Step-by-step explanation:

One pipe fills up 1 / 20th of the tank in one hour while the other fills up 1 / 30th of the tank in one hour. Therefore, together they fill up 1 / 20 + 1 / 30 i.e., (3 + 2) / 60 or 1 / 12th of the tank in one hour. Therefore, together they can fill up the tank in 12 hours but 1 / 3rd of the tank empties because of the leak. Therefore, the pipes need to fill up 1 - 1 / 3 i.e., 4 / 3rd of the tank which will take (4 / 3) / (1 / 12) i.e., 48 / 3 i.e., 16 hours. Ans.