There have been some posts asking mathematical questions, and others have reminded me of some counterintuitive probability problems. Start with the most difficult one first.
It is assumed that the dice described below are "true" dice. Id est: Each face has the same probability of being face up (1/6 or odds of 5 to one against).
Imagine three custom made dice which do not have 1-6 on the faces like standard dice. One die is red, one blue, and one green. If you were to examine these dice, you would notice that no two dice use the same numbers. You would also notice that each die has less that 6 different numbers on it.
Imagine playing and betting on a game in which one player owns the blue, the other owns the green die. The winner of each roll is the one whose die has the larger number. Neither player is bright enough to examine the two dice and figure out the probabilities. However, the owner of the green die notices that he loses about 5 out of nine rolls, with no ties (In fact, the odds favor the blue die over the green die by 5 to 4). The losing player demands to use the blue die. The other player agrees, but says he will use the red die. Once again, the same player loses about 5 out of nine rolls, with no ties (In fact, the odds favor red over blue by 5 to 4). Now, the losing player demands to use the red die and insists that the other player use the green die. Can you guess or calculate the odds in a game using the red & green die?
I can describe a set of three dice which conform to the above conditions, but I am not sure that it is the only possible "unique" set. The set that I have in mind can be used to figure out how to make trivially different sets. It will be interesting if anybody comes up with more than one set of dice conforming to the above conditions.
On to easier problems using a set of identical dice. Each die has "T" on three faces, and "H" on three faces. I could have used 3 zeros & 3 ones to make it easier for the real binary-thinking computer nerds to understand. I also could have suggested 3 different lewd pictures of a nude female and three of a nude male to make it easier for others of you to visualize the dice.
If I roll one such die 4 times, what is the probability (or odds) of getting "H" four times? How about getting "THHH?" Are odds the same? What about rolling 4 dice at one? Do the odds on rolling "H" four times change? Is it the same or different from "H" 3 times & "T" once?
Now consider a slightly different situation. Suppose we roll one die millions of times, recording the sequence of rolls (theoretical mathematicians do not worry about how long such procedures take). We expect the sequence to include "H" approximately as often as "T." We do not expect "H" & "T" to alternate (Id est: We do not expect "HTHTHTHTHTHTHTHT..."). Suppose we examine the recorded sequence, and count how many times we see "HHHH" and how many times we see "THHH." Do we expect to see the same number of each in an extremely long sequence? Do we expect to see one sequence occur before the other?
If anyone shows an interest, I will post answers to the above questions.
