How long will it take for the pool to completely fill with water? (explain why so i understand) it’s a 120 gallon pool

First, you find out how much can be filled in 1 minute. Then you divide that into 120 to get your answer. 

To find out how much can be filled in 1 minute, take the time and divide it into the volume. We'll use the second row (2 minutes and 8 gallons.)

8/2=4. So it takes 1 minute to fill 4 gallons. Now, you just divide 4 into 120. 

120/4=30

It takes 30 minutes to fill the pool up to 120 gallons. 

It would take 30 min to fill up the pool