Souce: https://canvas.ucsd.edu/courses/55106/assignments/syllabus

Section 1.1

There are roughly 240 students in this class. Which of the following is closest to the probability that at least 2 students share the same birthday?

a. 1%
b.
c.
d. 99%
e. 100%

Use of Probability in History

1600s - Gambling
1900s - Quantum Mechanics
1950s - Finance/Stock Market
2000s - Machine Learning

Modern rigorous formulation of probability theory due to Kolmorgorov in 1933.

Common Ingredients In Models of Randomness:

Probability Space

A probability space is a triple (), where

sample space () - collection of possible outcomes, i.e. {HH, HT, TH, TT}

collection of events () - An event is a subset of , i.e. , A=“1st flip is T”={TH,TT}, A=“at least 1 H”={HH,HT,TH}, ,

probability measure ()

a function from

satisfying Kolmorgorov’s axioms:

(A disjoint from B (meaning A and B can’t happen)})
= “empty set”

Area() = area() + area()

If is a sequence of disjoint events, then

disjoint means