Question 931935
Two pipes together can fill a tank in 6 hours.
 Pipe 1 alone can fill the tank in 10 hours.
 In how much time can pipe 2 fill the tank alone?
:
let x = time required by pipe 2 to fill the tank alone
let a full tank = 1
each pipe will do a fraction of the job, the two fractions add up to 1
{{{6/10}}} + {{{6/x}}} = 1
multiply by 10x, cancel the denominators and you have
6x + 10(6) = 10x
6x + 60 = 10x
60 = 10x - 6x
60 = 4x
x = 60/4
x = 15 min for pipe 2 to fill it alone
:
;
confirm this
 {{{6/10}}} + {{{6/15}}} = 1
.6 + .4 = 1