Category Probability

The Ballot Theorem

Today’s post is going to be about politics. Consider an election where there are two candidates, call them A and B, who receive votes respectively, and let us assume that . Assume that all possible “trajectories” are equally likely. What is the probability that candidate B is ahead of A throughout the vote counting procedure? […]

Martingales & Coins: Waiting for Heads-Tails-Heads

Consider the following simple problem: let be a sequence of independent fair coin tosses. How many times do we have to toss the coin in expectation in order to observe the sequence HTH (H stands for heads and T for tails)? We will answer this question here with three different ways. The first way is […]