5.2 Permutations and combinations · Count arrangements with repeated letters, with two people together or apart, and selections, then check each formula against a full list.
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About this lab
Count arrangements with repeated letters, with two people together or apart, and selections, then check each formula against a full list.
You will be able to
Calculate the number of arrangements of the letters of a word with repeated letters, such as NEEDLESS, by dividing n! by k! for each letter repeated k times.
Determine the number of arrangements in a line in which two particular people must stand together (treat them as one block and multiply by 2!) or must not (total minus together).
Distinguish a permutation from a combination, and calculate ⁿCᵣ = ⁿPᵣ ÷ r! for a selection, checking each count against a list of every case.
