Question 1132167
.
<pre>
(a)  In all, there are  {{{C[30]^5}}} = {{{(30*29*28*27*26)/(1*2*3*4*5)}}} = 142506 different ways to select group of 5 persons from 30 persons.


     The group of 5 youngest persons of 30 is the UNIQUE such group of 5 persons from 30, under given conditions.


     So, the probability you are looking for is  {{{1/142506}}}.     <U>ANSWER</U>



(b)  {{{C[11]^4}}} = {{{(11*10*9*8)/(1*2*3*4)}}}.

     Use your calculator.



(c)  {{{C[8]^6}}} = {{{(8*7)/(1*2)}}} = 28.     <U>ANSWER</U>
</pre>

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All these problems/questions are about COMBINATIONS.


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.