2 dice - 1/6 - 16.67%
3 dice - 1/6 + (2/6) * (1 - .1667) = 44.44%
4 dice - 1/6 + (2/6) * (1 - .1667) + 3/6 * (1 - .4444) = 72.22%
5 dice - 1/6 + (2/6) * (1 - .1667) + 3/6 * (1 - .4444) + 4/6 * (1 - .7222) = 90.74%
6 dice - 1/6 + (2/6) * (1 - .1667) + 3/6 * (1 - .4444) + 4/6 * (1 - .7222) + 5/6 * (1 - .9074) = 98.46%
7 dice - 1/6 + (2/6) * (1 - .1667) + 3/6 * (1 - .4444) + 4/6 * (1 - .7222) + 5/6 * (1 - .9074) + 6/6 * (1 - .9846) = 100%
If I made any mistakes in my calculations please let me know. I can explain these numbers to anyone who has questions. But I tried to make them easy to follow without using variables by simply adding the odds that the last die matches on of the other dies if there is not already a match each time we add a die.
When we look at it more closely, it seems quite obvious that among 5 dice you would have more than a 5/6 (which is 83%) chance of getting a double, since the other fallacious calculation would mean when you roll 6 dice you would have a 6/6 or 100% chance of getting a double which is ludicrous since you could roll one of each and would imply that when you roll 7 dice you have a 7/6 chance of getting a double which doesn't even make sense since it is over 100%. It seems people are fallaciously mixing up the average statistics of a specific roll/match (e.g. what are the odds of rolling a three) versus the odds of getting any match. Obviously, the latter is more likely than the former. Obviously, it is more likely to get at least either two ones, two twos, two threes, two fours, two fives or two sixes than to specifically get two sixes.
"The mind is a wonderful servant but a terrible master."
I believe spiritual freedom (a.k.a. self-discipline) manifests as bravery, confidence, grace, honesty, love, and inner peace.
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