Answer:
The net change is a decrease of 1,280 feet
Explanation:
From the question, we understand that the hiking team has a work rate of 320 feet / hour
Now that are descending between the hours 1pm and 5pm, this means that they descended for a total of 4 hours.
Now the total number of feet they have descended will be the number of hours * work rate = 4 hours * 320 feet/hour = 1,280 feet
Thus, the net change is decrease of 1,280 feet