8 ) Midterm , 2005 Suppose a free bus operates between the SFU Burnaby campus and the Downtown campus . There are two buses per day . The departure...

8 ) Midterm , 2005 Suppose a free bus operates between the SFU Burnaby campus and theDowntown campus . There are two buses per day . The departure time of the bus is randomThe first bus departs at 9:15 9:30 , or 9:45 . The second bus departs at 10:10 10:30 , or 10:40The departure times of the two buses are independent of one another , and have the followingprobability distributionBus I Departure Time9:15 am9:30 am9:45 amProbability1/61/21/3Bus 2 Departure Time10:10 am10:30 am0:40 amProbability1 161/21/3a ) Explain what the phrase " the departure times of the two buses are independent meanb ) If you arrive at the bus stop at 9:00 how long do you expect to wait for a free bus todepart ?( ) If you arrive at the bus stop at 9:20 how long do you expect to wait for a free bus todepart ?