Simple & Compound Events MathBitsNotebook.com Terms of Use   Contact Person: Donna Roberts
Dealing with ONE "event" ...
 Simple Event (or single event)
A simple (or single) event is an event with a single outcome.
 Simple Probabilities (with only one outcome, or desired result): • The probability of rolling a 3 on a die. (1/6) • The probability of drawing the ace of hearts from a deck of cards. (1/52) • The probability of tossing a head with a penny. (1/2) • The probability of rolling an even number less than 5 on a die. (2/6 = 1/3)

Dealing with MORE THAN ONE "event" ...
 Compound Event
A compound event is the combination of two or more simple events (with two or more outcomes).
 Compound Probabilities (with more than one outcome (desired result) within a trial ): • The probability of rolling an even number on a die, then tossing a head on a    penny. (3/12 = 1/4) • The probability of tossing three pennies and getting at least 2 heads.    (4/8 = 1/2) • The probability of drawing a heart from a deck of cards, replacing the card,    then drawing a spade.   (169/2704 = 1/16) • The probability of drawing a red ace from a deck of cards, not replacing the    card, then drawing a black ace. (2/52 • 2/51 = 4/2652 = 1/663) Independent events: multiply the two probabilities          Dependent events (one affects the other): multiply the probability of the first event          times the probability of the next event after the first event has taken place

 Remember: When dealing with probability (especially compound probability), a tree diagram may b e helpful to "see" what is happening.

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