(x+y)^n= ✅the sum from k=0 to k=n of: [(n choose k)*x^(n-k)*y^k
(x1+x2+...+xr)^n= ✅the sum over all n1,n2...,nr such that n1+n2+...+nr=n of: [(n choose
n1,n2,...,nr)*x1^n1*x2^n2+...+xr^nr
Probability space ✅...
How many ways to pair up 20 people ✅20!/(2^10*10!)
How many handshakes in 20 person room? ✅20 choose 2
Sample Space ✅The set of all possible outcomes of an experiment
Event ✅Any subset of the sample space
Mutually Exclusive ✅Two events, A and B, such that A intersect B is the empty set
The Two Versions of the Distributive Laws ✅1. A intersect (B union C)=(A intersect B) union (A intersect
C)
2. A union (B intersect C) = (A union B) Intersect (A union C)
Demorgan's Law ✅1. (A union B)^c=A^c intersect B^c
2. (A intersect B)^c=A^c union B^c
State the three probability axioms ✅A probability function is a junction with a domain of all events
within sample space, S, with the properties: