Math again ... I'm basing this on an answer Atticus gave me in one of the previous threads some months ago, and am pretty sure it's correct, but would appreciate some confirmation.
When rolling three twenty-sided dice, the chance for
... three totally different numbers is 1 * 19/20 * 18/20 = 342/400.
... any double or triple is therefore 58/400.
... any triple is 1 * 1/20 * 1/20 = 1/400.
... any double but not triple is 58/400 - 1/400 = 57/400.
... three 20s is 1/20 * 1/20 * 1/20 = 1/8000.
... two 20s but not three is 1/20 * 1/20 * 19/20 = 19/8000.
... at least two 20s is 20/8000.
Correct?