MathDB
Flipping coins, again

Source:

August 5, 2005
probabilityrationumber theoryrelatively prime

Problem Statement

Let pp be the probability that, in the process of repeatedly flipping a fair coin, one will encounter a run of 5 heads before one encounters a run of 2 tails. Given that pp can be written in the form m/nm/n where mm and nn are relatively prime positive integers, find m+nm+n.