Question

Sung-Hi is filling a sandbox with sand at the rate shown in the table below. which statement must be true regarding the linear function that represents this situation?

Answer 1

4th one is correct!

Explanation:

The rate of change must be 20 pounds per minute

since every minute there's 20 more pounds. Hope this helps!

Answer 2

D. The rate of change must be 20 pounds per minute.

Explanation:

At time 0, the amount of sand is 200 lb. Time zero is when it starts, so it is also called the initial time. The initial value is 200 lb, so choices A and B are wrong.

Now look at the difference from time 0 minutes to time 1 minute. The amount of sand went from 200 lb to 220 lb. The amount of sand placed in 1 minute is 20 lb, so the rate of change is 20 lb per minute. That makes choice C wrong and choice D correct.

Answer: D. The rate of change must be 20 pounds per minute.