Lesson Review:

1. The number of items in the list: a, a+1, …, b, b-1, where a≤b are integers, is b-a+1 (understand how it is derived).

2. Understand Venn Diagram

3. Count multiple events: (the number of ways A can occur) times (the number of ways B can occur)

4. Permutation: selelct r items in order from a group of n items in P(n,r) ways:

P(n,r) = n x (n-1) x (n-2) x … (n-r+2) x (n-r+1) = n!/(n-r)!

5. Factoral: n! = n x (n-1) x (n-2) x … 3 x 2 x 1

Homework:

Page 5: Ex 1.2.1, 1.2.2, 1.2.6

Page 12: Ex 1.3.1, 1.3.3

Page 18: Ex 1.4.1, 1.4.3, 1.4.5

Page 21: Ex. 1.5.1 (a) (c), 1.5.2