<PRE><B>Question 398415</B>
I think i may be on the right track but not sure. Here is the problem: One hose can fill a pool in 20 hours. Another hose can fill the pool in 16 hours. How long would it take the two hoses, working together to fill the pool? 
-----
Equation: 
rate + rate = together rate
1/20 + 1/16 = 1/t
Multiply thru by 80t to get:
4t + 5t = 80
9t = 80
time to fill the pool together is t = 80/9 hrs.
================
Cheers,
Stan H.
</PRE>