I'm trying to justify the combination formula in my head. I arrived at the following conclusion: The combination of n different objects taken r is equal to the product of the number of arrangements divided by the number of times in which each case is just a repetition of another in which there is a reversal of position. So I thought: the number of cases where there are these reversals of positions is equal to "r" for the first position (because there are "r" positions) "r-1 " for the second position, because I can't repeat the first one, and so on. until I get to r!. So the formula is: n!/r!(n-r)! Is this thought correct?
2026-04-09 18:15:34.1775758534
combinatorial analysis
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