"In the game of craps you roll two 6-sided dice. A sum of 2, 11, or 12 is considered a failure while all others are considered a success. Find the probability of rolling exactly 5 successes in 13 rolls."
I tried setting up the values for the formula nCx*P^x*Q^n-x but however, I am stuck finding the value of p which is probability of success. At first i got 8/11 but i am not certain if that is right or not.