Answer:
6 minutes.
Explanation:
She ascends at a rate of 5 feet per minute from the reef.
Once she reaches a height of -30 feet, she must rest for 15 minutes and she then continues to the surface at the same rate.
So, she dives from - 30 feet height to water surface i.e. 0 feet height with a rate of 5 feet per minute.
Therefore, she will take
minutes to reach the surface.
(Answer)