Permutations and Combinations Vocabulary

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Permutations and Combinations Vocabulary

• Essential Question What are permutations and
  combinations used for?

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Factorial

• A factorial is the product of all positive number
  less than or equal to a certain number.
• Its notation is an exclamation point (n!)
• For example, 6! 654321

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Permutation

• An ordering of objects
• Used for selecting items out of a group and
  ordering them (order is important!)
• If you have a group of n objects and you want to
  pick r of them to put in order the formula is

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Some examples of permutations

• Choosing people from a class to be class officers
• Choosing numbers for a locker combination
• Choosing books to go on a shelf in alphabetical
  order

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Combination

• An selection of items out of a group where order
  is NOT important
• If you have a group of n objects and you want to
  pick r of them out and order doesnt matter the
  formula is

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Some examples of combinations

• Choosing people from a class to be in a group
• Choosing toppings to put on a pizza
• Choosing books to go on a shelf in any order