Question

Your hose fills a swimming pool in 3 hours. When your friend's hose is used together with your hose, the pool is full in 1 hour. How long (in hours) does it take your friend's hose to fill the pool when working alone

Answer 1

1.5 hours

Explanation:

Given :

My hose = 3 hours ; my rate = 1/3

Let My friend's time = x ; his rate = 1/x

Combined time = 1 hour, combined rate = 1/1 = 1

Combined rate :

1/3 + 1/x = 1

1/x = 1 - 1/3

1/x = (3 - 1)/ 3

1/x = 2/3

Cross multiply :

3 = 2x

x = 3/2

x = 1.5 hours