SOLUTION: Ralph knows that there are 15 distinguishable possibilities when 2 people are chosen to form a committee from a particular group of N people. A) describe what values if N would be

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Question 891547: Ralph knows that there are 15 distinguishable possibilities when 2 people are chosen to form a committee from a particular group of N people.
A) describe what values if N would be admissible in this problem
B) Determine the number of people in the larger group, N
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
Ralph knows that there are 15 distinguishable possibilities when 2 people are chosen to form a committee from a particular group of N people.
A) describe what values if N would be admissible in this problem.
X%28X-1%29%2F2%21%22%22=%22%2215
X%28X-1%29%22%22=%22%222%2A15
X%5E2-X%22%22=%22%2230
X%5E2-X-30%22%22=%22%22%220%22
%28X-6%29%28X%2B5%29%22%22=%22%22%220%22

X-6=0,  X%2B5=0
X=6,    cross%28X=-5%29

So the number to pick 2 from in order to have 15 distinguishable possibilities
is 6.

Every time we pick 2 from the 6, we leave 4 behind. So there are also
15 ways to choose 4.  C(6,2) = C(6,4) = 15

So the admissible numbers we could pick 15 ways from the 6 are 2 and 4.

B) Determine the number of people in the larger group, N
Isn't it just asking for the larger group of 4?  (Am I missing something?)

Edwin