So their are 60 min in an hour. you multiply 60 min times 6 (hours). you get 360 min. Then you divide that by 90 min and you get 4
Answer it orbits 4 times
hope that helps
First covert 39.5% to a decimal to get 0.395.
0.395 written as a fraction is

Simplify

to get
Answer:
The statement describes that:
A person can be 9595 percent sure that the mean drive through service period of this chain is between 164.5164.5 seconds and 168.3168.3 seconds.
Your answer of 20% of 60 is 12