That doesn't work: if twenty of your friends told you it was raining, your method would tell you the probability was (2/3)^20 P(R), which is very small. Your m

That doesn't work: if twenty of your friends told you it was raining, your method would tell you the probability was (2/3)^20 P(R), which is very small. Your method was my first thought too - it took a while before I saw how to do it.