SOLUTION: Rate of Descent. A plane descends to sea level from 12,000 ft after being airborne for 1 1/2 hr. The entire flight time is 2 hr 10 min. Determine the average rate of descent of the

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Rate of Descent. A plane descends to sea level from 12,000 ft after being airborne for 1 1/2 hr. The entire flight time is 2 hr 10 min. Determine the average rate of descent of the      Log On


   

Question 984235: Rate of Descent. A plane descends to sea level from 12,000 ft after being airborne for 1 1/2 hr. The entire flight time is 2 hr 10 min. Determine the average rate of descent of the plane.
Book's answer is 300ft/min. I tried several methods but couldn't get 300ft/min for my answer. Please help.
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Rate of Descent. A plane descends to sea level from 12,000 ft after being airborne for 1 1/2 hr. The entire flight time is 2 hr 10 min. Determine the average rate of descent of the plane.
Book's answer is 300ft/min. I tried several methods but couldn't get 300ft/min for my answer. Please help.
=========================
It's not a clearly stated problem. "after being airborne for 1 1/2 hr." implies the descent started then but is not explicit.
----
2 hr 10 - 1 hr 30 = 40 minutes
12000 ft/40 min = 300 ft/min
=============================================
It's another instance of people who don't know what they're talking about writing math books.
They should stick to politics.