Robert stands atop a 1,380-foot hill. He climbs down, reaching the bottom of the hill in 30 minutes. What is Robert's average rate of elevation change in feet per minute?

A.

+460

B.

+46

C.

-46

or

D.

-460

-46 feet/min

Step-by-step explanation:

Initial elevation = 1,380 ft

Final Elevation = 0 feet

Change in elevation

= Final elevation - Initial Elevation

= 0 - 1,380

= - 1,380 feet

Given that the journey took 30 min,

rate of descent = Change in elevation / time

= - 1,380 / 30

= - 46 feet/min