1. I: Laws of Probbability J: Independent Events

2.  Write what formulas we know on the board.  What other formulas are on the Mathematics SL formula booklet (5.5 & 5.6)?

8.  In a class of 25 students, 14 like pizza and 16 like iced coffee. One student likes neither and 6 like both. One student is randomly selected from the class. What is the probability that the student: ◦ Likes pizza? ◦ Likes pizza given that he or she likes iced coffee?

9.  In a class of 25 students, 14 like pizza and 16 like iced coffee. One student likes neither and 6 like both. One student is randomly selected from the class. What is the probability that the student: ◦ Likes pizza? ◦ Likes pizza given that he or she likes iced coffee?

10. The top shelf in a cupboard contains 3 cans of pumpkin soup and 2 cans of chicken noodle soup. The bottom shelf contains 4 cans of pumpkin soup and 1 can of chicken noodle soup. Jimmy is twice as likely to take a can from the bottom shelf as he is from the top shelf. Suppose Jimmy takes one can of soup without looking at the label. Determine the probability that it: a) is chicken. b) was taken from the top shelf given that it is chicken.

11. The top shelf in a cupboard contains 3 cans of pumpkin soup and 2 cans of chicken noodle soup. The bottom shelf contains 4 cans of pumpkin soup and 1 can of chicken noodle soup. Jimmy is twice as likely to take a can from the bottom shelf as he is from the top shelf. Suppose Jimmy takes one can of soup without looking at the label. Determine the probability that it: a) is chicken. b) was taken from the top shelf given that it is chicken.

13. Mutually Exclusive EventsIndependent Events  Definition of a mutually exclusive event If event A happens, then event B cannot, or vice- versa. The two events "it rained on Tuesday" and "it did not rain on Tuesday" are mutually exclusive events.  When calculating the probabilities for exclusive events you add the probabilities.  Independent events The outcome of event A, has no effect on the outcome of event B. Such as "It rained on Tuesday" and "My chair broke at work".  When calculating the probabilities for independent events you multiply the probabilities. You are effectively saying what is the chance of both events happening bearing in mind that the two were unrelated.

14. Clear as mud?