A hose can fill a swimming pool in 18 hours.Another hose needs 3 more hours to fill the pool than the two hoses combined.How long would it take the second hose to fill the pool?
A) 9 hours
B) 14 hours
C) 18 hours
D) 6 hours
E) 12 hours

Question

A hose can fill a swimming pool in 18 hours.Another hose needs 3 more hours to fill the pool than the two hoses combined.How long would it take the second hose to fill the pool? 
A) 9 hours
B) 14 hours
C) 18 hours
D) 6 hours
E) 12 hours

Quizplus · Accepted Answer

The first hose can fill the pool in 18 hours, so it fills 1/18 of the pool in 1 hour. The two hoses combined can fill the pool in 18 hours, so they fill 1/18 + 1/x of the pool in 1 hour, where x is the number of hours it takes the second hose to fill the pool. Since the second hose needs 3 more hours to fill the pool than the two hoses combined, we have 1/18 + 1/x = 1/15. Solving for x, we get x = 14 hours.

A Hose Can Fill a Swimming Pool in 18 Hours