Question

The inlet pipe of an oil tank fills it in 1 hour 30 minutes. The outlet pipe can empty the tank in 1 hour. How long will it take to empty a full tank if both pipes are open?

Answer 1

To find the time it takes to empty a full tank when both pipes are open, divide the tank's capacity by the combined rate of the inlet and outlet pipes.

Step-by-step explanation:

To find the time it takes to empty a full tank when both pipes are open, we need to determine the combined rate at which the two pipes fill or empty the tank. Since the inlet pipe can fill the tank in 1 hour 30 minutes, its rate is 1/1.5 tank per hour. Similarly, the outlet pipe can empty the tank in 1 hour, so its rate is 1 tank per hour. When both pipes are open, their combined rate is (1/1.5 - 1) tank per hour.

To empty a full tank, we divide the tank's capacity by the combined rate.

Let's assume the tank's capacity is C. So, the time it takes to empty the full tank when both pipes are open is C / ((1/1.5 - 1) tank/hour).