Question 23843
First of all let;
x=Jim's hose
x-.20x=Bob's hose
x+(x-.20x)=18
2x-.20x=18
1.8x=18
x=10
So now we have what Jim's hose would do, and we know Bob's hose takes 20% less time, so;
10-.20=2
So bob's hose;
10-2=8
Now the two together;
10+8=18
=)