**Videos for Section 4.1 WebAssignments**

*These videos have been tested with Chrome, Firefox, Safari, and IE 11. If you run into issues viewing the videos with any web browser, please let us know.*

**Videos for Section 4.2 WebAssignments**

Set operations and Venn diagrams (17:49)

**Videos for Section 4.3 WebAssignments**

Venn diagrams and data (15:50)

Venn Diagram Example (6:36)

**Videos for Section 4.4-4.5 WebAssignments**

Multiplication principle and tree diagrams (19:10)

Permutations and Combinations (29:29)

Counting ways to pick a committee (4:34)

Example of Venn Diagram for organizing data (6:35)

Counting patterns (4:56)

Some review problems (17:43)

More review problems (14:50)

House Inspections (11:28)

Designing Tables (9:37)

Wrong Solutions (14:58)

**Additional Resources:**At Khan Academy, counting techniques (Part 4 of this course) and probability applications (Part 5 of this course) are all mixed up together. The only counting videos that don't include probability concepts seem to be one on permutations and one on combinations. However, a large number of illustrations of counting techniques appear in the Khan Academy videos mentioned in Part 5 below. So you'll get some good review of counting techniques if you consult those videos when you get to Part 5. [Note: The Khan Academy videos and most mathematical texts use a different notation for combinations and permutations from what you find in our own videos. What we denote by C(5,3), i.e. the number of combinations in which 3 objects can be chosen from 5 objects, is denoted in most texts by 5C3, and similarly P(5,3) is written generally as 5P3.]