Question 1110975
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<pre>
1.  You can choose seven of 15 by {{{C[15]^7}}} ways to the first, 7-seating wheel.

    {{{C[15]^7}}} = {{{(15*14*13*12*11*10*9)/(1*2*3*4*5*6*7)}}}.



2.  You can choose five of remaining 15-7 = 8 by {{{C[8]^5}}} ways to the second, 5-seating wheel.

    {{{C[8]^5}}} = {{{(8*7*6*5*4)/(1*2*3)}}}.


3.  And that is all.  The remaining  15-7-5 = 3 persons are just uniquely defined, and you have nothing more to select.



4.  So, your final answer is the product of these two numbers:

    {{{C[15]^7}}} . {{{C[8]^5}}}


5.  I leave it to you to complete these calculation.
</pre>

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On Combinations, &nbsp;see the lessons

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF =http://www.algebra.com/algebra/homework/Permutations/Introduction-to-Combinations-.lesson>Introduction to Combinations</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF =http://www.algebra.com/algebra/homework/Permutations/PROOF-of-the-formula-on-the-number-of-combinations.lesson>PROOF of the formula on the number of Combinations</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF =http://www.algebra.com/algebra/homework/Permutations/Problems-on-Combinations.lesson>Problems on Combinations</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF =https://www.algebra.com/algebra/homework/Permutations/OVERVIEW-the-lessons-on-Permutations-and-Combinations.lesson>OVERVIEW of lessons on Permutations and Combinations</A>

in this site.


Also, &nbsp;you have this free of charge online textbook in ALGEBRA-II in this site

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-II - YOUR ONLINE TEXTBOOK</A>.


The referred lessons are the part of this online textbook under the topic &nbsp;"<U>Combinatorics: Combinations and permutations</U>". 



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.