Question

Use the image to answer the question.


The graph shows the number of gallons in a wading pool that is being drained. Using the points (1,160)
(
1
,
160
)
and (3,80)
(
3
,
80
)
as (x1,y1)
(
𝑥
1
,
𝑦
1
)
and (x2,y2)
(
𝑥
2
,
𝑦
2
)
, what is the rate of change in the number of gallons in the pool after each hour has passed?

(1 point)
Responses

140
1
40
gal./hr.

Answer 1

Slope = (80 - 160) / (3 - 1) = -80 / 2 = -40, so the pool is losing 40 gallons per hour (rate = -40 gal/hr).