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 in 1 hour it can fill 1/18 of the pool. The two hoses combined can 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 two hoses combined can fill the pool in 18 + 3 = 21 hours, we have:1/18 + 1/x = 1/21Solving for x, we get:x = 18 * 21 / (21 - 18) = 126 / 3 = 42Therefore, the second hose would take 42 hours to fill the pool.

A Hose Can Fill a Swimming Pool in 18 Hours