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You are not logged in. #1 20120731 19:07:28
Combinations and Permutations CalculatorI am using the powerful Combinations and Permutations Calculator, but #2 20120731 19:51:24
Re: Combinations and Permutations CalculatorHi passegua 2)The two digits are different. We can choose one in 7 ways and another one in 6 ways (because we said they were different), but the order in which we choose them doesn't matter (eg. choosing a 4 and a 7 is the same as choosing a 7 and a 5) so we will have to divide the number by 2. The number of ways in which we choose the two digits is . Now we have 6 digits (2 ones, 2 twos and two different digits). Again, we can permute the number in 6! ways, but, again, changing the 2 ones' places with each other doesn't change anything so we need to divide by 2. Same goes for the 2 twos, so we end up dividing 6! by 4. Notice that this time we are not dividing by 2 for the two remaining digits because they aren't the same. The number of permutations for this case is Now that we know the results for the two cases and are sure we didn't miss any number in these cases, we get the final answer by adding the two results, which gives us: Last edited by anonimnystefy (20120731 19:52:47) The limit operator is just an excuse for doing something you know you can't. “It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman “Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment #3 20120801 00:07:13
Re: Combinations and Permutations CalculatorHi; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #5 20120802 16:23:48
Re: Combinations and Permutations CalculatorHi passegua; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. 