How much time does it take to fill the pool?

Question

A swimming pool gets filled up in 8 hours through a pump there water can run through at 50litres pr minute. How much time does it take to fill up the pool with a pump that gives 2.5litres per second?

Answer 1

First, convert 2.5 liters per second to liters per minute.  The are 60 seconds per minute.

 

(2.5 l/s)*(60 sec/min) = 150 liters/minute

 

You can now set up the proportion.  Note that the time is inversely proportional to the rate, rate ∝ 1/time:

 

 50 l/m          x hours

------------  =  -------------

150 l/m         8 hours

 

 1        x

---- = ----

 3        8

 

Cross multiply:

 

8 = 3x

 

Solve for x.