A fair 6-sided die is rolled three times. Find the probability that the sum of the three dice is 4 ?
1 Answer
Nov 7, 2017
Explanation:
Since the die is a 6-sided die (described as being "fair", meaning all possible outcomes from 1 to 6 are equally possible/probable), we know that overall there are
Now we want to enumerate all of the outcomes that result in a sum of 4. Since we're getting a minimum of 1 on each die (which gives us a total of 3), the only way we can get a sum of 4 on three rolls of a die is if we have a set of 1, 1, and 2. This means one of the die rolls will be a 2. Since we're rolling three times, there's three possibilities:
{1,1,2}, {1,2,1}, {2, 1, 1}
Thus, the probability is