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

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


   

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) About Me  (Show Source):
You can put this solution on YOUR website!
.

7 items can be selected from 18 items by  C%5B18%5D%5E7 ways.


C%5B18%5D%5E7 is the number of combinations of 18 items taken 7 at a time.


C%5B18%5D%5E7 = 18%21%2F%287%21%2A%2818-7%29%21%29 = %2818%2A17%2A16%2A15%2A14%2A13%2A12%29%2F%281%2A2%2A3%2A4%2A5%2A6%2A7%29.


Calculate it on your own.

-----------------

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.