# Bernoulli Trials

The sum of N identical Bernoulli RV's is a binomial(N, p) [call the sum X], p being the parameter for the Bernoulli. The first step is to find p, which you can get by solving $P(X = 2) = P(X = 0)$ for the parameter p, noting that for the general binomial random variable that $P(X = x) = \binom{n}{x} p^x (1-p)^{n - x}$.