SOLUTION: An aquarium tank can hold 6600 liters of water. There are two pipes that can be used to fill the tank. The first pipe alone can fill the tank in 66 minutes. The second pipe can fil

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: An aquarium tank can hold 6600 liters of water. There are two pipes that can be used to fill the tank. The first pipe alone can fill the tank in 66 minutes. The second pipe can fil      Log On


   

Question 321016: An aquarium tank can hold 6600 liters of water. There are two pipes that can be used to fill the tank. The first pipe alone can fill the tank in 66 minutes. The second pipe can fill the tank in 55 minutes by itself. When both pipes are working together, how long does it take them to fill the tank?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The rate for 1st pipe is (1 tank)/66 min
The rate for 2nd pipe is (1 tank)/55 min
Their rates of filling the tank with both open
is the sum of the 2 rates working alone
Let x = time to fill with A&B both open
1%2Fx+=+1%2F66+%2B+1%2F55
Multiply both sides by 330x
330+=+5x+%2B+6x
11x+=+330
x+=+30
It takes 30 min with both pipes open
Note that the liters of water in a full tank is not needed to solve