Question

Working together, it takes two different sized hoses 20 minutes to fill a small swimming pool. If it takes 30 minutes for the larger hose to fill the swimming pool by itself, how long will it take the smaller hose to fill the pool on its own? Do not do any rounding.

Answer 1

60 minutes for the larger hose to fill the swimming pool by itself

Explanation:

It is given that,

Working together, it takes two different sized hoses 20 minutes to fill a small swimming pool.

takes 30 minutes for the larger hose to fill the swimming pool by itself

Let x be the efficiency to fill the swimming pool by larger hose

and y be the efficiency to fill the swimming pool by larger hose

To find LCM of 20 and 30

LCM (20, 30) = 60

To find the efficiency

Let x be the efficiency to fill the swimming pool by larger hose

and y be the efficiency to fill the swimming pool by larger hose

x = 60/30 =2

x + y = 60 /20 = 3

Therefore efficiency of y = (x + y) - x =3 - 2 = 1

so, time taken to fill the swimming pool by small hose = 60/1 = 60 minutes