Answer:
1. 12/1= rate of change
Step-by-step explanation:
1.
1 mile= 30 seconds
(1,30)
6 miles= 1 1/2 minutes
6 miles=90seconds
(6,90)
Formula: y2-y1/x2-x1
90-30/6-1
60/5
12/1= rate of change
hope its right
Let's call

the number of hours it takes for A to fill the pool and

the number of hours it takes for B to fill the pool.
We have

and

hence

hence

and thus

.
1/2 of a gallon if the pool will be gone each hour