Let Bi (i = 1, 2, 3) be three independent events in a sample space. The probability that only B1 occur is $\alpha$, only B2 occurs is $\beta$ and only B3 occurs is $\gamma$. Let p be the probability that none of the events Bi occurs and these 4 probabilities satisfy the equations $$\left( {\alpha - 2\beta } \right)p = \alpha \beta$$ and $$\left( {\beta - 3\gamma } \right)p = 2\beta \gamma$$(All the probabilities are assumed to lie in the interval (0, 1)). Then $${{P\left( {{B_1}} \right)} \over {P\left( {{B_3}} \right)}}$$ is equal to $\underline{\hspace{2cm}}$.