Question

Nola hiked down a trail at a steady rate for 10 minutes. Her change in elevation was -200 feet. Then she continued to hike down another 20 minutes at a different rate. Her change in elevation for this part of the hike was -300 feet. During which portion of the hike did she walk down at a faster rate? Explain your reasoning.

Answer 1

The correct answer is:

The faster rate is when she hiked down 200 feet in 10 minutes.

Explanation:

The rate of change is given by the change in y over the change in x; in this case, the change in elevation over the change in time.

For the first part of the hike, the change in elevation was -200 and the change in time was 10; this gives us a rate of change of -200/10 = -20.

For the second part of the hike, the change in elevation was -300 and the change in time was 20; this gives us a rate of change of -300/20 = -15.

She hiked downhill faster during the first part of the hike, at 20 feet per minute.