eli5: Two die probability

222 views

When calculating probability for two standard die, 4,2 and 2,4 are treated as two separate outcomes. By that logic, why aren’t doubles treated the same way? One outcome for die A and B rolling 3,3 and another for die B and A rolling 3,3.

In: 5

4 Answers

Anonymous 0 Comments

Imagine the dice are actually laying out on the table: die A shows four pips and die B shows two. You could physically pick up A and turn it into a two, and physically pick up die B and turn it into a four.

Now do the same with a pair of threes: You cannot change either of them from a three to a different three. There is only one three on each die, and so there is only one actual result out of 36 potential ones where both roll a three.

**Edit:** If it helps to have a visual, [here](https://www.edcollins.com/backgammon/diceposs.gif) is an image showing every possible result to rolling two six-sided dice.

You are viewing 1 out of 4 answers, click here to view all answers.