The associative property could be that they are both even and they are both in the 3x table
I am not sure, but this is what I got:
<span>Pipe ALONE = 18 hours
Pipe ALONE in 1 hour = 1/18 of the pool
Hose ALONE in 1 hour = 1/25 of the pool
TOGETHER in 1 HOUR = 1/18 +1/25 = 43/450
TOGETHER they will fill the pool in 450/43 hours
So 5/6 of the pool will take 5/6 X 450/43 = 2250/ 258 = 8.7209302 hours OR
8 hours AND 43.26 minutes ANSWER
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Hope this helps!