From a group of 20 students, 8 of whom are computer science majors and 12 of whom are electrical engineering majors, one student is selected at random, and then a second student is selected at random from the remaining 19 students. Let A be the event that the first student is a computer science major,and let B be the event that the second student is a computer science major. Prove that A and B are dependent events.
I tried to use P(A|B)=P(A intersect B)/P(B) should not be equal to P(A), but I'm running into trouble with the numbers. Is P(A intersect B)=(8/20)(7/19)? And is P(B)=(8/19) or (7/19)? Very confused.