Solve the problem. See Example 3.Filling a Settling Pond  A sewage treatment plant has two...

Solve the problem. See Example 3.

Filling a Settling Pond  A sewage treatment plant has two inlet pipes to its settling pond. One can fill the pond in 10 hr, the other in 12 hr. If the first pipe is open for 5 hr and then the second pipe is opened, how long will it take to fill the pond?

EXAMPLE 3

SOLVING A WORK RATE PROBLEM