Review of Probability

This is simple if you remember the difference between mutually exclusive and not mutually exclusive.

Notes:

If two events are mutually exclusive, then they cannot happen at the same time.

P(A or B) = P(A) + P(B) - P(A & B).

-If the events are not mutually exclusive, then P(A or B) = P(A) + P(B).

Ex 1: A standard deck of cards consists of 52 cards, with 13 cards in each of four suits (clubs, spades, diamonds, and hearts). Clubs and spades are black, and diamonds and hearts are red. The face cards consist of jacks, queens, and kings. Assuming the deck is shuffled properly, what would be the probability that a card is:

• red = 26/52 = 1/2
• A black club = 13/52 =1/4
• blue = 0/52 = 0
• A jack = 4/52 = 1/13

-Sameer