How do I explain this to other students?

#1
This is a problem that a student I am tutoring brought to me and I am not sure how to solve it or explain it to him, can you give me any suggestions?

Busses headed for Chicago leave the bus station exactly every 15 minutes starting at 6:00am while buses headed for Rockford leave the station exactly every 15 minutes starting at 6:05 am.
a.) A passenger arrives every day at the station at a random time uniformly distributed between 6 am and 7 am and takes the first bus that leaves the station. What percentage of the time will she go to Chicago?

b.) IF she arrives at a time uniformly distributed but between 6:10 and 7:10, what percentage of the time will she go to Chicago?
 

JohnM

TS Contributor
#2
Using the bus schedules, determine the number of buses that leave for each destination within each time interval. The probability of going to a particular destination is the number of buses going to that destination within the time interval divided by the total number of buses leaving within the time interval.