Answer:
Time taken by A = 16 seconds
Time taken by B = 12 seconds
Explanation:
Given:
Two elevator and their respective time to reach certain height.
Here time is function of height.
Time taken by elevator A = 0.8(h)+16
Time taken by elevator B = -0.8(h)+12
We have to find the time taken by the elevator to reach ground level.
Accordingly:
We know that ground level the height will be zero meaning that (h=0).
Plugging the h values in the equation we can find the time taken by both the elevators to reach zero height that is the ground level.
⇒
⇒

⇒
⇒

⇒
sec ⇒
sec
So,
Time taken by elevator A and elevator B to reach the ground is 16 seconds and 12 seconds respectively.