# Chance of rolling at most one six with two dice in 20 rolls.

by lo2
Tags: chance, dice, rolling, rolls
 P: 55 1. The problem statement, all variables and given/known data Well as I said what is the chance of getting at most one six when rolling two dice twenty times? 2. Relevant equations I know the probability of getting one six in one roll with two dice is: 11/36 And not getting one is: 25/36 3. The attempt at a solution Then I figured out that the probability of not getting a 6 in $n$ rolls is equal to: $P = 1 - (\frac{25}{36})^n$ So is that so? And how do you calculate the proability of getting at most one 6 in twenty rolls?
 Mentor P: 12,037 I can confirm your probability of getting no 6 in all rolls. Your initial problem is unclear to me: What happens if you roll (6,6) one time and "no 6" the other 19 times? Your approach for a solution would include this in the probability, but the literal interpretation would not. Anyway: Can you calculate the probability to get exactly one 6 in 20 rolls? If not, here is an easier subproblem: A 6 in the first roll, and no 6 in the other 19. How does that help to calculate the probability of exactly one 6 in 20 rolls?
 Quote by lo2 1. The problem statement, all variables and given/known data Well as I said what is the chance of getting at most one six when rolling two dice twenty times? 2. Relevant equations I know the probability of getting one six in one roll with two dice is: 11/36 And not getting one is: 25/36 3. The attempt at a solution Then I figured out that the probability of not getting a 6 in $n$ rolls is equal to: $P = 1 - (\frac{25}{36})^n$ So is that so? And how do you calculate the proability of getting at most one 6 in twenty rolls?