Answer:
Part a)
![160\ gallons](https://img.qammunity.org/2020/formulas/mathematics/middle-school/oi29llyoelmncp11rwr1qpba1267qwr6ig.png)
Part b)
![480\ gallons](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ai7gklu29k8y308xq0lzl56lfpwrsvjhps.png)
Explanation:
Part a) How many gallons of water will be in the pool after 20 minutes?
we know that
Using proportion
![(40)/(5)(gallons)/(minutes)=(x)/(20)(gallons)/(minutes) \\ \\x=40*20/5\\ \\x=160\ gallons](https://img.qammunity.org/2020/formulas/mathematics/middle-school/cv3y69jto1rvyovanv2cgvaud4nvphsyp3.png)
Part b) How many gallons of water will be in the pool after 1 hour
we know that
1 hour = 60 minutes
Using proportion
![(40)/(5)(gallons)/(minutes)=(x)/(60)(gallons)/(minutes) \\ \\x=40*60/5\\ \\x=480\ gallons](https://img.qammunity.org/2020/formulas/mathematics/middle-school/nx5r53y6kp66ee1mudtetbpyowv7w5hu1m.png)