Thread: Wrong answer key or wrong me ?

. Two pipes running together can fill up a cistern in 3(1/3) minutes. If one pipe takes 3 minutes more than the other to fill the cistern, find the time in which each pipe would fill the cistern. [Ans: 8 min]

But I'm getting an irrational number,

what I did

let time of first pipe be x and time for second pipe be x-3

so the equation is

1/x + 1/(x-3) = 1
x^2 -5x + 3 = 0
from ehre it is clear taht an irrational root is obtained.....

I’ve just worked through the problem, and I think it should be minutes, not minutes.

Originally Posted by ice_syncer

so the equation is

1/x + 1/(x-3) = 1

No, the equation is



where is the fraction of the cistern filled in 1 minute by one of the pipes and in 1 minute by the other; is the fraction of the cistern filled in 1 minute by both pipes together.

Originally Posted by algebraic topology

I’ve just worked through the problem, and I think it should be minutes, not minutes.


No, the equation is



where is the fraction of the cistern filled in 1 minute by one of the pipes and in 1 minute by the other; is the fraction of the cistern filled in 1 minute by both pipes together.

LOL LOL thanks alot! I guess I'll report it to my math teacher
Ice Sync
(emo)