Answer:
The elevator will take you up at 300 feet in 36 seconds.
Explanation:
Let the time taken to go up 300 feet be = t seconds
Given is that the elevator takes you up at 500 feet in 60 seconds.
So, we can derive a relation as:

=>

=>

t = 36 seconds
So, the elevator will take you up at 300 feet in 36 seconds.