. 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.....