Quote:
Water enters a vat, whose capacity is 60 liters, through a faucet at the top and leaves the vat through a drain at the bottom. If the vat is empty, the drain is open, and water starts to flow through the faucet at a constant Rate of 5 liters per minute, it takes exactly 50 minutes until the vat is full. At what rate, in liters per minute, is water flowing through the drain?
For all rate problems remember the formula work = rate x time.
In this case, the capacity of the vat = 60L. Then, the vat fills at a rate of 5L/min, so were there no drain, the vat would fill in 60 ÷ 5 = 12 minutes.
However, there is a drain and we discover that the real amount of time to fill the vat is 50 minutes. So, therefore the real rate of filling is 60 ÷ 50 = 1.2 L/min.
Subtract the two found rates from each other to find the difference which will represent the rate of drain. 5 - 1.2 = 3.8 L/min pass through the drain.