You roll a fair dice. What is the probability that you will attain a three?

Answer 1

Roll it once, Pr(3) = 1/6

But if you meant roll 2 dice, Pr(3) = 2/36 = 1/18

there're 2 ways to get a sum of 3: 1 and 2, or 2 and 1

there are 36 different possible outcomes: 6^2 = 36