16.6 Probability: Simple Event OBJ:  To determine the probability of a simple event

DEF:  Probability of simple event P(E) = # of ways Event can occur # of ways possible

EX:  What is the probability that in a throw of a die a face with 4 dots will appear? 1 (face with 4 dots) 6 (faces on a die)

EX:  What is the probability that a face with an even number of dots will appear? 3 (faces with 2, 4, or 6 dots) 6 (faces on a die) 1 2

EX:  A bag contains 5 red balls and 4 black balls. One ball is drawn from the bag. What is the probability that it is black? 4 (black balls) 9 (balls in bag) What is the probability that it is white? 0 (white balls) 9 (balls in bag) 0 Impossible

DEF:  Probability of 1 and 0 1 = P (certain event) 0=P(impossible event) 0 < P(E) < 1 Probability (Event) is a proper fraction

EX:  A deck of cards contains 52 cards. One card is drawn. What is the probability that the card is an ace P (Ace) = 4 (Aces) 52 (cards in a deck) 1 13 that it is the ace of hearts? P (Ace of Hearts) = 1 (Ace of Hearts) 52 (cards in a deck) that it not an ace? P (ACE) = 48 (cards that are not aces) 52 (cards in a deck) 12 13

DEF:  Probability of an event not occurring _ P(E) = 1 – P (E) _ P (at least 1) = 1 – P(E)

DEF:  Odds Odds in Favor = P (E) 0r P (E) : P (E) Odds Against = P (E) 0r P (E) : P (E)

EX:  A bag contains 30 balls; 18 of them are red. What are the odds that the ball drawn will be red? P (red) = P ( red ) = Odds = P (R) = 3:2