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Combinationa nd Permutation

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Combinationa nd Permutation

by ajmoney09 » Sun Jan 18, 2009 9:23 pm
Can someone explain me the easiest way to figure out these questions....I always get lost on these problems. Seem to never get the right answer either. If someone has a quick fix for me that would be amazing. I am good at math so you wouldn't confuse me, as long as you explain your steps and don't skip any steps because reading it i would get lost. And if you have a gooood practice problem to post that shows the ins and out of these types that would be most useful as well.

Thanks,
AJ
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by logitech » Mon Jan 19, 2009 12:40 am
Check this out
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by ajmoney09 » Wed Jan 21, 2009 9:20 pm
Thanks Log

I will look over this.
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by gaggleofgirls » Wed Jan 21, 2009 10:12 pm
The big difference between combinations and permutations is that permutations have a specific order to them and combinations don't.

If I want a subcommitee of 3 out of a group of 5 (a,b,c,d,e), this is a combination - a,b,c is the same as b,a,c is the same as c,a,b and they all represent just a single choice.

If there is order involved, then it is a permutation. If I am going to pick the president, then VP then Sec of State from the group of 5 (a,b,c,d,e) then
a= pres, b=vp, c=SoS is NOT the same as b=pres, a=VP, c=SoS and also not the same as c=pres, a=vp, b = SoS (just ask Hillary if SoS is the same as Pres). Therefore each group (abc, bac, cab) represents a separate choice and must be counted as 3 of the options (not 1 option as above). So permutations will have more options than combinations.

Some words that point out permutations include: arranged, arrangements, ordered, respectively, and any sort of directional instructions like "left to right."

Hope that helps.

-Carrie
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