Calculating Probability: P(A or B) = P(A) + P(B) – P(A and B)
Example 1: A card is selected at random from a standard deck of 52 cards. What is the probability that the card will be a face card or a spade?
Example 2: In a class of 20 seniors, 17 have applied to a state university and 11 have applied to a private university. In all, 19 out of 20 have applied to a university. What is the probability that a class member chosen at random has applied to a state school and a private university?
Practice 1: Out of a group of 25 students, 12 are on the football team and 14 are on the baseball team. If 6 students do not play either football or baseball, how many student play both sports?
Practice 2: A pet store has 18 light green parakeets (5 females and 13 males) and 25 sky blue parakeets (15 females and 10 males). You randomly choose one of the parakeets. What is the probability that it is a male or a sky blue parakeet?