SOLUTION: Of 18 possible​ books, you plan to take 7 with you on vacation. How many different collections of 7 books can you​ take?

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Question 1153586: Of 18 possible​ books, you plan to take 7 with you on vacation. How many different collections of 7 books can you​ take?
Answer by ikleyn(52778)   (Show Source): You can put this solution on YOUR website!
.

7 items can be selected from 18 items by   ways.


 is the number of combinations of 18 items taken 7 at a time.


 =  = .


Calculate it on your own.

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This problem is on COMBINATIONS.

On Combinations,  see introductory lessons
    - Introduction to Combinations
    - PROOF of the formula on the number of Combinations
    - Problems on Combinations
    - OVERVIEW of lessons on Permutations and Combinations
in this site.

Also,  you have this free of charge online textbook in ALGEBRA-II in this site
    - ALGEBRA-II - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this online textbook under the topic  "Combinatorics: Combinations and permutations".


Save the link to this textbook together with its description

Free of charge online textbook in ALGEBRA-II
https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson

into your archive and use when it is needed.


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