3.2 Odds

 

Ex 1 There are a few coins in a jar: 3 pennies, 2 nickels, 4 dimes and a quarter.

(a) Let set A represent all the coins in the jar worth less than 8 cents.

(b) What is ?

(c) Describe the opposite of set A.  This is called the compliment of A.  It uses the notation .

(d) What is ?

 

‘Odds in favour of event A occurring’ are a ratio of the probability of event A occurring to the probability of event A not occurring.

 

Odds in favour of A

 

Ex 1 (d) What are your odds in favour of grabbing the quarter without looking?

 

Ex 2 In the semi-finals of a tournament, everyone agrees that all players have an equal chance of winning.  What are the odds in favour of player A winning?

 

Odds in favour of A

Odds against A                        

or                    

Odds in favour of A not occurring.

 

Ex 3 A university professor, in an effort to promote good attendance habits, state that the odds of passing her course are 8 to 1 when a student misses fewer than five classes.  What is the probability that a student with good attendance will pass?

 

If  then

 

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