Riddle -- Probability of Expectation

[alThor]

[ QUOTE ]
The chance of all 3 letters occurring in the same 36-character line is

0.756331278146836^3 = 0.432649477099284


[/ QUOTE ]

The occurrence of letters are not independent events. This number is therefore slightly off.

For instance, suppose we had an alphabet with 3 letters (A,B,C), and a "line" only contained two letters. This method would say that a letter does not occur in a line with probability (2/3)^2 = 4/9, so occurs at least once w/probability 5/9. But then the probability of seeing all three letters in a 2-letter line would be (4/9)^3. But there should be zero probability to have 3 different letters in a 2-letter line, so this doesn't work exactly.

alThor