Question 619271: how do you get better in knowing if the problem is permutation and combination and how do you know what numbers to use for each
Found 2 solutions by Alan3354, Theo:
Answer by Alan3354(69443)   (Show Source):
Answer by Theo(13342)  (Show Source):
You can put this solution on YOUR website! practice.
do problems involving them and you'll eventually see the relationships.
here's some links that can help you determine.
http://www.mathsisfun.com/combinatorics/combinations-permutations.html
http://www.omegamath.com/Data/d2.2.html
http://www.algebra.com/algebra/homework/Permutations/change-this-name6021.lesson
http://www.regentsprep.org/Regents/math/algtrig/ATS5/PCPrac.htm
http://www.scribd.com/doc/7240679/Permutation-and-Combinations-Test-15-Problems-and-Answers
the lessons will tell you that permutations are used when order is important and combinations are used when order is not important.
that's basically it, but only practice helps you to recognize the situations when combinations are asked for or where permutations are asked for.
some basics.
you select a team that includes members but roles within the team are not assigned - use combinations.
you select a team that includes members with each member assigned a specific role on that team - use permutations.
you want to get the first 3 winners of a race but order of each winner is not important - use combinations.
you want to get the first 3 winners of a race but order of each winner is important - use permutations.
permutations will give you more possible sets than combinations.
a set containing a,b,c is one set.
if order is not important, than all the set has to do is contain the members a,b,c in any order.
a,b,c or a,c,b or b,a,c or b,c,a or c,a,b or c,b,a doesn't matter - they're all considered part of the same set.
on the other hand, if order matters, then:
a,b,c or a,c,b or b,a,c or b,c,a or c,a,b or c,b,a does matter - each one of them is considered a separate set even if all of them contain the same members each.
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