Probability

Let \(\mathrm{S} = \{ {w_1},{w_2},......\}\) be the sample space associated to a random experiment. Let \(P({w_n}) = {{P({w_{n - 1}})} \over 2},n \ge 2\). Let \(A = \{ 2k + 3l:k,l \in N\}\) and \(B = \{ {w_n}:n \in A\}\). Then P(B) is equal to :