1. Answers 1.3/10 2.1/15 3.11/850 4.1/270725 5.4/35 6.7/15

2. Section 2-4: Computing Probabilities Using Equally Likely Outcomes CFU 3126.5.7 Use a variety of counting methods to … determine probabilities

3. What We Have Done… O Basic Probability O N(E)/N(S) O Permutations/Combinations O Now we are just putting them together! O We will use permutations and combinations to fill in our N(E) and N(S) spots!

4. Hints O Fill the denominator in first! O Remember that how many we are choosing on the top needs to equal how many we are choosing on the bottom O Sometimes, the problem won’t say all of the ones which get picked, so think through the story in order to make sure it works.

5. Sample Problems O A 12-unit apartment building has 9 smoke alarms which pass inspection and 3 which do not. If 3 smoke alarms are selected at random and tested, what is the probability that they will all pass inspection? O What is the probability that exactly 2 pass inspection?

6. Sample Problems O A total quality management team contains 8 people: 5 from customer service and 3 from data processing. Two team members are selected at random to make a presentation. What is the probability that exactly 1 member is selected from customer service?

7. Sample Problems O A student has 5 coins – 2 dimes and 3 quarters – and 2 coins are selected simultaneously and at random. Find the probability that both are quarters. O Find the probability that at least 1 is a dime.

8. Sample Problems O Sam and Sally are members of a committee containing 4 men and 3 women. A subcommittee of 3 people is going to be chosen from the group. What is the probability that both Sam and Sally will be included? O What about only one of them?

9. Classwork/Homework O Worksheet and p. 60 #9, 11, 13, 15, 17 O Homework Quiz Tomorrow O Chapter 2 Test will be on Thursday

10. Sample Problems O An accounting firm regularly audits 4 firms each year. It has 4 chief auditors who direct these audits and the assignment of the chief auditors is at random. What is the probability that all 4 auditors will be assigned to the same firm they were assigned to last year?