Answer:
Cheeta's speed = 10 feet per second
Gazelle's speed = 10 feet per second
Hence, They run at the same speed.
Step-by-step explanation:
Determining the Cheeta's speed:
Covered distance = 60 feet
Time taken = 6 seconds
Speed = Covered distance / Time taken 
            = 60 / 6
            = 10 feet per second
Therefore, Cheeta's speed is 10 feet per second.
Determining the Gazelle's speed:
Covered distance = 100 feet
Time taken = 10 seconds
Speed = Covered distance / Time taken 
            = 100 / 10
            = 10 feet per second
Therefore, Gazelle's speed is 10 feet per second.
Conclusion:
Cheeta's speed = 10 feet per second
Gazelle's speed = 10 feet per second
Hence, They run at the same speed.