Question 146208

OK, we'll deal in minutes
Let x=amount of time it takes all three working together to fill the pool
Jim fills at the rate of 1/30 pool per min
Sue fills at the rate of 1/45 pool per min
Tony fills at the rate of 1/90 pool per min

Together they fill at the rate of 1/30+1/45+1/90=
3/90 + 2/90 + 1/90=6/90  pool per min

So, our equation to solve is
(6/90)x=1(1 pool that is) multiply each side by 90
6x=90  divide each side by 6

x=15 min-------------------time it takes all three working together


Hope this helps---ptaylor