Question

Interpret the slope as a rate of change for the following situation. Be sure to give the appropriate units:

The relationship between the number of gallons in a swimming pool (y) and time in minutes (x) is graphed and forms a line. The slope of the line is -4.
Three of the following statements based on that situation are false. Select the statement below that is TRUE.

A. The pool is draining at rate of 240 gallons per hour.
B. The pool is filling up at a rate of four gallons per minute.
C. The pool is draining at a variable rate over time.
D. The pool is filling up at a rate of 240 gallons per hour.

Answer 1

Since the slope is negative, it would mean the gallons would be decreasing over time, meaning the pool is draining. So neither B or D.
Now you can figure out how many gallons is draining per hour by multiplying:
4(60)=240. So the pool is draining at a rate of 240 gallons per hour.

I would choose A.