jeff@hpcnoe.UUCP (12/16/85)
Surprisingly, there seems to be some confusion about what the
probabilities of throwing certain number with two dice. This is an
attempt to settle the matter (so we can get these rail baron
probabilities down).
The simplest way I can explain it is that the two dice are independent
of each other (one does not affect the other), therefore the different
possible rolls are show in the following table:
1 2 3 4 5 6
----------------
1 | 2 3 4 5 6 7
2 | 3 4 5 6 7 8
3 | 4 5 6 7 8 9
4 | 5 6 7 8 9 10
5 | 6 7 8 9 10 11
6 | 7 8 9 10 11 12
There are 36 entries in the table, equally likely to be thrown. There
are 2 entries for 3, therefore the probability of throwing a 3 would be
2/36 = 5.56%. This can be summarized as:
2 : 1/36 = 2.78%
3 : 2/36 = 5.56%
4 : 3/36 = 8.33%
5 : 4/36 = 11.11%
6 : 5/36 = 13.89%
7 : 6/36 = 16.67%
8 : 5/36 = 13.89%
9 : 4/36 = 11.11%
10 : 3/36 = 8.33%
11 : 2/36 = 5.56%
12 : 1/36 = 2.78%
-- Jeff Wu
..!ihnp4!hpfcla!j_wu