9000 ft
Step-by-step explanation:
Given: A airplane is ascending at a constant rate of 15 feet per second,
What we need to know: The change in altitude during 10 minutes of flight,
60 seconds = 1 minute
60 × 10
= 600 seconds
600 × 15
= 9000 ft
Therefore there was a 9000 ft change in altitude during the 10 minutes of the flight.