Pipe A runs 10 liters of water per minute into a tank that has a total volume of 1,200 liters. Pipe B fills an half the tank in 1 hours.
Working together how long will it take both pipes to fill the tank ?	Pick
A) 2 hours and 36 minutes B) 1.5 hours C) 9 hours and 12 minutes D) 15 hours E) 1 hour and 12 minutes.
Pipe A has a rate of 10 liters per minute which equals a rate of 600 liters per hour.   Pipe B has a rate of 400 liters per hour.   400 + 600 (A+B) = Together they have a rate of 1000 liters per hour.   1200 (The tank ) / 1000 = 6/5 = 1 hour and 12 minutes   Answer -1 hour and 12 minutes.
<result>E</result>
Pipe A runs 10 liters of water per minute into a tank that has a total volume of 1,200 liters. Pipe B fills an half the tank in 1 hours.
Working together how long will it take both pipes to fill the tank ?