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6 Cards in this Set
- Front
- Back
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What are counting methods in maths ?
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Factorial , Permutation , combination
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What is factorial ?
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Calculate certain things in order.
Count n things one after other. n!= n*n-1*n-2*n-3...1 |
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What is permutation and combination used for?
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Calculate when u need to calculate or pick "r" things from total "n" things
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What is Permutation ?
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pick 'r' from 'n' things.
(ORDER) + (No REPLACEMENT ) nPr = n! / (n-r)! |
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What is combination ?
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pick 'r' from 'n' things.
(no order)+ (no replacement) nCr = n! / (n-r)!r! |
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special case of Combination
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pick 'r' from 'n'
(no order)+ (repalcement) canbe done in n raise to r ways. |
