Two Pipes Can Fill A Tank In 20 And 24 Minutes Respectively And A Waste Pipe Can Empty 3 Gallons Per Minute. All The Three Pipes Working Together Can Fill The Tank In 15 Minutes. The Capacity Of The Tank Is:

[RahulMishra74430]

Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is:

[Jonathan-Joe]

To get you started - consider what proportion of the tank's content each pipe provides in one minute.

[Hymie]

You need to take into account that over the 15 minutes it took for the tank to fill – the waste pipe discharged 45 gallons.

[Gizmonster]

Let me get you started:
Let the capacity of the tank = C gallons
Pipe 1 fills at a rate of C/20 gallons per min
Pipe 2 fills at a rate of C/24 gallons per minute
Waste pipe empties at a rate of 3 gallons per minute
When all 3 pipes are running, the tank fills in 15 minutes.

You need to solve the following equation:
[(C/24) + (C/20) - 3] x 15 = C

Work out what C is and you'll have the capacity of the tank in gallons.

[bobbinwales]

120 gallons???

[bobbinwales]

Ha started mine 30 mins ago and didn't see yours gizmonster.... wonder if yours gives same as me?

[bobbinwales]

I done first one is 3 tanks an hour and next is 2.5 per hour so 5.5 in total. Then lose 180gs per hour. That as to equal 4 tanks an hour

[Gizmonster]

Yea same answer bobbin .... although I was trying not to do all the work for the OP :)

[Jonathan-Joe]

I thought it would be best to encourage Rahul Mishra to work through the problem step by step. They might then learn how to tackle similar problems in future.

[bobbinwales]

I doubt the op would getmany marks just for the answer tho ... if there given the answer they can work backand that might help them just as much maybe more forget time

[bobbinwales]

^Forget time = for next time