7. Sets:Blitzstein 1, Orloff 1a, 1b, Sheffield 3
8. Probability function: Blitzstein 2, Orloff 2, Sheffield 4, 5
10. Conditional probability and independence: Blitzstein 3, 4, Orloff 3, Sheffield 6, 7
11. Combinatorics: khan comb, Blitzstein 5, 6, Sheffield 1, 2
