Discuss midterm:

- No crypto
- Copy your questions to a Word file if you're worried

The first "question" is a list of these formulas:

¬∀x P(x) is the same as ∃x ¬P(x). Same if you reverse ∀ and ∃.

(n choose k) = n! / (n-k)!k! = n×(n-1)×...×(n-k+1) / k×(k-1)×...×3×2×1

Counting overlapping sets: |A∪B| = |A| + |B| - |A∩B|

Summing an arithmetic series: reverse the order and add by column. All columns will be the same.

Summing a geometric series with ratio r: calculate rS - S, where S is the sum.

Stars and Bars: when making k choices spread
over n categories (k cookies to n children, or k scoops of ice cream
from n flavors, or alphabetically ordered strings of letters of length
k, from among n letters)

Use k stars, and n-1 bars.

a|b: a divides b: ∃k ak = b

Modular arithmetic mod n: divide by n and take the remainder.

Fermat's little theorem: if p is prime, then
a^{p} ≡ 1 mod p for all a ≢ 0

See pld.cs.luc.edu/courses/163/spr22/mnotes/probability.html.

Poker

Dice

Bayesian vs Frequentist understanding of probability

Monty Hall

Wednesday

Monty reprise

Birthdays

Binomial distribution

Poisson distribution

Bayes' formula