## MAT118 Review for Midterm II

2.3 Understand the "Fundamental Principle of Counting."
Example 1, Problems 4 and 5.
Understand the factorial 5! = 5 4 3 2 1 notation and how to use it in counting how many ways n objects can be ordered.
Example 3, Example 4. Problems 19,20.

2.4 Understand the difference between "permutation" and "combination."
Example 2, Problem 18.
Example 5, Example 8, Problem 35.

3.2 Understand the "basic probability terms" and know the definition of "Probability of an Event" (p.122).
Example 3, Problems 6,7,8,9.
Understand how probabilities occur in genetics.
Example 4, Problems 61,62,63.

3.3 Understand the "probability rules" (p.135 and p.139) and be able to tell if two events are mutually exclusive.
Example 2.
Especially Rule 4: p(EUF) = p(E) + p(F) - p(E^F). Know how to interpret this rule in terms of a Venn Diagram.
Example 4, Problems 60,61.

3.4 Understand how "combinations" enter into calculating probabilities.
Example 3 and Example 4 <--understand these! Problems 15,16,19,20.

3.5 Know the definition of "Expected Value" and how to compute it.
Example 1 is a good one. Problems 14,15.
Harder problems like 20,21,22 are worth knowing. Problem 23.

3.6 Know the definition of "Conditional Probability" and how to compute it as in Example 1.
Understand the rule p(A^B) = p(A)p(B|A) and how to use it as in Example 2.
Problems 3-6, Problems 33-36.

November 10 1999