Suppose the container holds x cubic feet of water.
a pipe can fill a container with water in 3 hrs.
So the pipe's fill rate is x cu.ft. per 3 hours. or or
However, if water is drawn from it at the same time at the rate of 4 cubic ft per hour,
That means the new slower fill rate is the pipe's original fill rate
reduced by to
it requires 5 hrs to fill it.
So this new slower fill rate is also x cu.ft. per 5 hours. or or .
So we equate the two expressions for the new slower fill rate:
= .
Multiply thru by LCD of 15
5x - 60 = 3x
2x = 60
x = 30 cu ft, which is how much the container holds.
At what rate is the pipe delivering water?
Since the pipe's fill rate is , that becomes:
, or 10,
Edwin