What is the combination formula that keeps being mentioned in the answer key on chapter 6?
-Dannialles
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- dddannie6
- Course Students
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- Joined: Mon May 07, 2012 12:36 pm
- tommywallach
- Manhattan Prep Staff
- Posts: 1917
- Joined: Thu Mar 31, 2011 11:18 am
Re: Word Problems - Combinatorics
Hey DDDannie,
If you read my other post (http://www.manhattanprep.com/gre/forums/word-problems-combinatorics-t9723.html?sid=a2c4653eaabddbec902fdb271ea775d5), you'll see that I don't actually recommend using any formulas. However, the formulae in question are:
Permutations (order does matter): Picking k objects from a set of n
(n!)/(n-k)!
Combinations (order doesn't matter): Picking r objects from a set of n objects:
(n!)/(r! * (n - r)!)
But, as I said, I do not recommend using these formulas on the test. The slots method is much better.
-t
If you read my other post (http://www.manhattanprep.com/gre/forums/word-problems-combinatorics-t9723.html?sid=a2c4653eaabddbec902fdb271ea775d5), you'll see that I don't actually recommend using any formulas. However, the formulae in question are:
Permutations (order does matter): Picking k objects from a set of n
(n!)/(n-k)!
Combinations (order doesn't matter): Picking r objects from a set of n objects:
(n!)/(r! * (n - r)!)
But, as I said, I do not recommend using these formulas on the test. The slots method is much better.
-t
2 posts Page 1 of 1