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A club has 8 executive board members and 15 general members. How many committees of 6 can be chosen if it must consist of at least 4 executive boards? ​

Sagot :

Answer:

There are 8218 possible ways that a committee of 6 can be chosen if it must consist of at least 4 executive board members.

Step-by-step explanation:

This is a problem that involves combination. Combination is a combinatoric concept that deals with the number of distinct objects chosen from a set of objects disregarding the order of the objects.

The formula for the combination is given by [tex]\begin{aligned}_nC_r=\frac{n!}{r!(n-r)!}\end{aligned}[/tex].

Some Fundamental Principle of Counting Concepts

  • Combination
  • Permutation

Solution:

The phrase "at least 4 executive boards" means that the number of executive board member can be 4 or it can be greater than 4.

We can take the combination of each case, then add all the possible outcomes.

Case 1: 4 from executive board members and 2 from general members

            We can choose 4 out of 8 and 2 out of 15 to form the committee.

               [tex]\begin{aligned}_8C_4 \times _{15}C_2 &=\frac{8!}{4!(8-4)!}\times \frac{15!}{2!(15-2)!}\\&=70\times105\\&=7350\end{aligned}[/tex]

              There are 7350 ways we can choose 4 from the executive board members and 2 from general members to form the committee of 6 members.

Case 2: 5 from executive board members and 1 from general members

              We can choose 5 out of 8 and 1 out of 15 to form the committee.

               [tex]\begin{aligned}_8C_5 \times _{15}C_1 &=\frac{8!}{5!(8-5)!}\times \frac{15!}{1!(15-1)!}\\&=56\times15\\&=840\end{aligned}[/tex]

              There are 840 ways we can choose 5 from the executive board members and 1 from general members to form the committee of 6 members.

Case 3: 6 from executive board members.

              We can choose 6 out of 8 to form the committee.

                [tex]\begin{aligned}_8C_6&=\frac{8!}{6!(8-6)!}\\&=28 \end{aligned}[/tex]

              There are 28 ways we can choose 6 from the executive board members to form the committee of 6 members.

Adding all the possible cases, we have 7350 + 840 + 28 = 8218

Thus, there are 8218 possible ways we can choose a committee of 6 consisting of at least 4 executive board members.

To learn more about combinations, go to

  • Example of Combination and Permutation: https://brainly.ph/question/1994449
  • Reflection about combination: https://brainly.ph/question/504738
  • Difference between combination and permutation: https://brainly.ph/question/103634

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