2014 AIME II Problem 6

Charles has two six-sided die. One of the die is fair, and the other die is biased so that it comes up six with probability \frac{2}{3} and each of the other five sides has probability \frac{1}{15}. Charles chooses one of the two dice at random and rolls it three times. Given that the first two rolls are both sixes, the probability that the third roll will also be a six is \frac{p}{q}, where p and q are relatively prime positive integers. Find p+q.

Leading zeroes must be inputted, so if your answer is 34, then input 034

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.