Math Is Fun Forum

arkticcool

Member

Registered: 2008-02-22

Posts: 1

Worded Problems Leading to Quadratic equations

There are two pipes, Pipe A and Pipe B. Pipe A fills a tank in four minutes less than B does. If both pipes are open the tank is filled in 24 minutes. Find the time A will take if B is closed.

A quick post is neccasary, Thanks to anyone in advance that solves it.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Worded Problems Leading to Quadratic equations

Suppose the volume of the tank is V. If Pipe A alone takes t minutes to fill it, Pipe B alone will take t+4 minutes. So, in one minute, Pipe A alone fills a volume of V⁄t while Pipe B alone fills a volume of V⁄(t+4). Hence, when both pipes are open, they will fill a volume of V⁄t + V⁄(t+4) in one minute. Since it takes 24 minutes for the tank to be full, we have

Now solve that equation to get t.

Last edited by JaneFairfax (2008-02-22 21:57:42)