SOLUTION: A large pipe can empty the pool in 6 hours and a small pipe can empty the same pool in 9 hours.How long will it take for both pipes to empty the pool?

Question 1042552: A large pipe can empty the pool in 6 hours and a small pipe can empty the same pool in 9 hours.How long will it take for both pipes to empty the pool?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Rate of emptying for large pipe:
[ 1 pool emptied ] / [ 6 hrs ]
Rate of emptying for small pipe:
[ 1 pool emptied ] / [ 9 hrs ]
---------------------------
Add their rates of emptying to get
the rate with both pipes together
Let = time in hrs with both
pipes emptying together
---------------------------

Multiply both sides by

-------------
Both pipes together will empty the pool in
3.6 hrs
----------------
check:

Error due to rounding off
OK
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