Computers in a shipment of 100 units contain a portable hard drive, CD RW drive, or both according to the following table:
Portable hard drive
Yes No
CD RW
Yes 15 80
No 4 1
Let A denote the events that a computer has a portable hard drive and let B denote the event that a computer has a CD RW drive. If one computer is selected randomly,
compute (a) P (A)
(b) P (A ∩ B)
(c) P (A U B)
(d) P (A’ ∩ B)
(e) P (A|B)