SOLUTION: A swimming pool can be filled in 6 h and requires 9 h to drain. If the drain was accidentally left open for 6 h while the pool was being filled, how long did filling the pool requi

Question 5692: A swimming pool can be filled in 6 h and requires 9 h to drain. If the drain was accidentally left open for 6 h while the pool was being filled, how long did filling the pool require?
Answer by prince_abubu(198) (Show Source): You can put this solution on YOUR website!
This problem requires two parts. Part I would be to find the amount of the pool filled during the first six hours while the pool was left to be able to drain. Part II would be to figure out how long it would take the filling pump to fill the remaining volume of the pool, assuming that they closed the drain.

Part Zero. This is a r*t = w type problem. From reading the problem, it might not be obvious how you find the rate, work and time, and that the values 6 hrs and 9 hrs look very tempting to plug into the t. Actually, if the pool took 6 hours to fill, that took 6 hours to do 1 job. So, using r*t = w, r * 6 = 1. Solving for r will get you the pump's filling rate, which is 1/6 of the pool per hour. Likewise, for the drainage rate, it takes 9 hours to drain it. In other words, 9 hours to do 1 job. So drain * 9 = 1, then drain = 1/9.

Part I. The first six hours. Obviously, if it takes the pump alone to fill the pool in the first six hours, we're done. But the drain was left open. Obviously, if it drained in the first six hours, the pump did not fill the pool.

<---- So only 1/3 of the pool is actually filled in the first 6 hours.
RELATED QUESTIONS
A swimming pool can be filled in 6 hours and requires 9 hours to drain. If the drain was... (answered by Fombitz)

A swimming pool can be filled in 6 hours and requires 9 hours to drain. If the DRAIN was... (answered by josgarithmetic)

A swimming pool can be filled in 12 hours, and requires 18 hours to drain. If the drain... (answered by Fombitz)

A swimming pool can be filled by a pipe in 6 hours and it requires 9 hours to drain it.... (answered by Edwin McCravy)

A swimming pool is to be filled using two pipes that individually can fill the pool in 8... (answered by scott8148)

A large and small drain are opened to drain a pool.The large drain can empty the pool 6... (answered by scott8148)

A large and small drain are opened to drain a pool. After both drains have been opened... (answered by fners)

i need your help with word problem i never seem to understand the this one in particular... (answered by solver91311)

A pool takes 6 hours to fill and 9 hours to drain. If the drain is left off for 6 hours... (answered by Fombitz)