Question

You are flying on an airplane from Hanoi, Vietnam, to Manila, Philippines. After a few hours, the pilot announces that the plane has begun its descent at a constant rate to land at the Manila airport. After descending for 5 minutes, the plane's elevation is 10 kilometers. After descending for 15 minutes, its elevation is 6 kilometers. What is the total number of minutes that the plane spends descending before it lands?

Answer 1

you can use distance = rate * time

Answer 2

and you have a constant rate of descent (a straight line)