A hiker is walking down a mountain. She walked​ 5,978 feet in 17 minutes. In that​ time, she descended​ 1,024 feet from the top of the mountain. She then walked​ 3,972 feet in 7 minutes. In that​ time, she descended 500 more feet. Express the average rate of change in altitude of the hiker from her starting point to her ending point as a unit rate.

Accepted Solution

first walk=descend of 1024 feet in 17 minutes
second walk=descend of 500 feet in 7 minutes

so in total she descended 1024+500=1524 feet in 7+17=24 minutes
as an average rate this equals 1524/24=63.5 feet/minute descended
or an average rate of -63.5 feet/minute in altitude (note the minus)