If a hose sprays 8/15 of a liter every quarter of an hour how long will it take to get 1 liter

Question

Shawn is watering his garden and knows his plants need 1 liter of water. If the hose spray 9/15 of a liter ever 1/4 of an hour how long will take to water shan't garden?

Answer 1

Consider each spray as a unit. 

He needs 15/9 of a unit for each spray.      1 ÷ 9/15

Now each spray takes 1/4 of an hour.

The total times is (15/9)(1/4) or 15/36 of an hour.

 

Answer 2

First calculate the rate, or speed of water sprayed per hour.

 

(8/15 L) / (0.25 hr) = 2.133 L/hr

 

You want to find the amount of time it takes for 1 L. So divide this by the rate to cancel out Liters and find the hours.

 

(1 L) / (2.133 L/hr) = 0.469 hrs

 

If you want the answer in minutes

 

0.469 hrs * (60 min) / 1 hr = 28.125 min