SOLUTION: A box of 10 articles contains one that is defective. In how many ways can Ken select 4 articles such that the defective article is included?

Question 1175061: A box of 10 articles contains one that is defective. In how many ways can Ken select 4 articles such that the
defective article is included?
Answer by ikleyn(52778) (Show Source): You can put this solution on YOUR website!
.


In   ways, by adding 3 arbitrary articles taken at a time from 9 good articles.


The number    is   = 84.    ANSWER

Solved, answered and explained.

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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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