SOLUTION: Tap A takes 6 min to fill a tank and Tap B takes 9 min to fill the same tank. Pipe C can empty the tank in 15 min. How long will it take to fill up the tank if the pipe is in use w

Algebra ->  Proportions  -> Lessons -> SOLUTION: Tap A takes 6 min to fill a tank and Tap B takes 9 min to fill the same tank. Pipe C can empty the tank in 15 min. How long will it take to fill up the tank if the pipe is in use w      Log On


   

Question 1078848: Tap A takes 6 min to fill a tank and Tap B takes 9 min to fill the same tank. Pipe C can empty the tank in 15 min. How long will it take to fill up the tank if the pipe is in use when both taps are turned on?
Please help me with this as soon as possible!! Thank you.
Found 2 solutions by josgarithmetic, ankor@dixie-net.com:
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
1%2F6%2B1%2F9-1%2F15, rate in TANK/MINUTES for all three (the two taps and the one pipe) open at the same time

LCD, 2%2A3%2A3%2A5=90


%281%2F6%29%2815%2F15%29%2B%281%2F9%29%2810%2F10%29-%281%2F15%29%286%2F6%29

15%2F90%2B10%2F90-6%2F90

19%2F90

How much time?
90%2F19

4 minutes 44 seconds

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Tap A takes 6 min to fill a tank and Tap B
takes 9 min to fill the same tank.
Pipe C can empty the tank in 15 min.
How long will it take to fill up the tank if the pipe is in use when both taps are turned on?
:
let t = time required to fill the tank in minutes
Let a full tank = 1;
Use plus for fill and minus for empty
t%2F6 + t%2F9 - t%2F15 = 1
multiply equation the least common multiple, 90
90*t%2F6 + 90*t%2F9 - 90*t%2F15 = 90*1
Cancel the denominators
15t + 10t - 6t = 90
19t = 90
t = 90/19
t = 4.737 minutes