1. **Problem Statement:**
(A) How many ways can a 4-person subcommittee be selected from a committee of 8 people?
(B) How many ways can a president, vice-president, secretary, and treasurer be chosen from a committee of 8 people?
2. **Formulas and Rules:**
- For (A), selecting a subcommittee means choosing 4 people out of 8 without regard to order. This is a combination problem.
- The formula for combinations is $$\binom{n}{r} = \frac{n!}{r!(n-r)!}$$ where $n$ is the total number of people and $r$ is the number chosen.
- For (B), choosing distinct officers means order matters because each position is different. This is a permutation problem.
- The formula for permutations is $$P(n,r) = \frac{n!}{(n-r)!}$$
3. **Calculations:**
(A) Given $n=8$ and $r=4$:
$$\binom{8}{4} = \frac{8!}{4!\times(8-4)!} = \frac{8!}{4!\times4!}$$
Calculate factorials:
$$8! = 40320, \quad 4! = 24$$
So:
$$\binom{8}{4} = \frac{40320}{24 \times 24} = \frac{40320}{576} = 70$$
(B) Given $n=8$ and $r=4$:
$$P(8,4) = \frac{8!}{(8-4)!} = \frac{8!}{4!}$$
Calculate factorials:
$$8! = 40320, \quad 4! = 24$$
So:
$$P(8,4) = \frac{40320}{24} = 1680$$
4. **Explanation:**
- For (A), since the order does not matter, we use combinations and find there are 70 ways.
- For (B), since each position is unique, order matters, so we use permutations and find there are 1680 ways.
**Final answers:**
(A) 70
(B) 1680
Committee Selection 020C57
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