MathDB

2004 Combinatorics #4

Source:

December 30, 2011

probability

Problem Statement

Andrea flips a fair coin repeatedly, continuing until she either flips two heads in a row (the sequence

\texttt{HH}

) or flips tails followed by heads (the sequence

\texttt{TH}

). What is the probability that she will stop after flipping

\texttt{HH}