A plane takes off and climbs steadily for 15 minutes until it
reaches 30,000 feet. It travels at that altitude for 2 hours until
it begins to descend to land, which it takes 15 minutes at a
constant rate.

A plane takes off and climbs steadily for 15 minutes until it reaches 30000 feet It travels at that altitude for 2 hours until it begins to descend to land whic class=