Question

A swimming pool can be filled in 5 hours by hose a alone and 6 hours by hose b alone. how long would it take to fill the pool using both hoses?

Answer 1

hose a =1/5 pool per hour
hose b=1/6 pool per hour
1/5+1/6=11/30 pool per hour
1/11/30=30/11 hours to fill the pool with both hoses
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