22+Combinations

=__**Combinations**__=

__**Summary**__: Combinations are counting problems where order doesn’t matter. For example hand of cards is a combination because no matter what order you put the cards in you still have the same hand while a telephone number would not be a combination because the order of the digits does matter. The goal in this section is to find the probability of an event that is a combination.

__**Rules/ Formulas/ Properties**__:
 * Order is NOT important! When order is important, the problem is a permutation.
 * [[image:BardachPic1.png width="188" height="76"]]
 * [[image:Bardach2.png width="479" height="52"]]

There is a **3.85%** (or **1/26**) probability that all boys will be picked.

 * __Example problem two__-**

In how many ways can you order a triple scoop of ice cream if there are 19 flavors and you don’t choose a single flavor for more than one scoop? Out of the 200 campers at sports camp, 4 were selected to participate in a baseball league. Of the 200 campers, 75 tried out for the league on the first day. What is the probability that a camper did not try out for the league was selected?
 * __Example problem three__-**

__**Websites**__**:** http://www.math-magic.com/probability/combinations.htm http://mathforum.org/dr.math/faq/faq.comb.perm.html http://www.mathwords.com/c/combination_formula.htm