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Order
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is important
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Order is NOT important
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Arrange
Permutations
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Arrange and Pick
Variations
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Pick
Combinations |
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Without repetition |
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How many ways are there to arrange 3 letters a,b,c?
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How many words of 2 different letters can you make with 4 letters a,b,c,d?
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How many ways are there to pick 2 different letters out of 4 letters a,b,c,d? [number of subsets]
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With
repetition |
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Example |
How many ways are there to arrange 2 letters a and 2 letters b?
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How many words of 2 letters can you make with 4 letters a,b,c,d?
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How many ways are there to pick 2 letters
out of 4 letters a,b,c,d? |
Dirk Van de moortel – 2003