Discuss the below:
Q: Among its various routes, a transit agency operates a trolley line. The line has a total of 18 trolley cars. Some of these cars are unavailable because they are being maintained or repaired. The probability distribution of Y = number of cars out of service on a randomly chosen day
A B
1 Y P(y)
2 0 0.28
3 1 0.16
4 2 0.11
5 3 0.10
6 4 0.08
7 5 0.07
8 6 0.05
9 7 0.04
10 8 0.04
11 9 0.03
12 10 0.02
13 11 0.01
14 12 0.01
a. What is the probability that all the trolleys are operating?
b. The agency needs at least 14 cars available for normal operation of the line. What is the probability that the operation will not be normal?