Answer:
Time taken by cheetah to catch up to the antelope is 4 seconds.
Explanation:
Given : A cheetah that is running 90 feet per second is 120 feet behind an antelope that is running 60 feet per second.
To find : How long will it take the cheetah to catch up to the antelope?
Solution :
Let 'x' be the time taken by cheetah to catch up to the antelope.
A cheetah that is running 90 feet per second.
Distance covered by Cheetah is

Antelope that is running 60 feet per second.
Distance covered by Antelope is

According to question,
Cheetah is 120 feet behind an antelope.
i.e.
(as distance remain same)
The time taken is 4 second.
Therefore, Time taken by cheetah to catch up to the antelope is 4 seconds.