1. ## 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.....

2. I’ve just worked through the problem, and I think it should be $3\frac{1}{\color{red}13}$ minutes, not $3\frac{1}{3}$ minutes.

Originally Posted by ice_syncer
so the equation is

1/x + 1/(x-3) = 1
No, the equation is

$\frac{1}{x}+\frac{1}{x-3}\ =\ \frac{1}{3\frac{1}{13}}$

where $\frac{1}{x}$ is the fraction of the cistern filled in 1 minute by one of the pipes and $\frac{1}{x-3}$ in 1 minute by the other; $\frac{1}{3\frac{1}{13}}$ is the fraction of the cistern filled in 1 minute by both pipes together.

3. Originally Posted by algebraic topology
I’ve just worked through the problem, and I think it should be $3\frac{1}{\color{red}13}$ minutes, not $3\frac{1}{3}$ minutes.

No, the equation is

$\frac{1}{x}+\frac{1}{x-3}\ =\ \frac{1}{3\frac{1}{13}}$

where $\frac{1}{x}$ is the fraction of the cistern filled in 1 minute by one of the pipes and $\frac{1}{x-3}$ in 1 minute by the other; $\frac{1}{3\frac{1}{13}}$ 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)