11 RAIN IN THE CITY

You are about to get on a plane to Mumbai, you want to know whether you have to bring an umbrella or not. You call N of your random friends and ask each one of them if it’s raining. The probability that your any friend is telling the truth is 2/3 and the probability that (s)he is playing a prank on you by lying is 1/3. If all N of them tell that it is raining, then what is the probability that it is actually raining in Mumbai.