Movie Selections F16581
1. **Problem statement:** You want to buy 5 movies in total: 3 sci-fi and 2 western. The store has 12 sci-fi movies and 8 western movies. How many ways can you choose these movies?
2. **Formula used:** The number of ways to choose $k$ items from $n$ items is given by the combination formula:
$$\binom{n}{k} = \frac{n!}{k!(n-k)!}$$
3. **Step 1: Calculate ways to choose 3 sci-fi movies from 12:**
$$\binom{12}{3} = \frac{12!}{3!(12-3)!} = \frac{12!}{3!9!}$$
Calculate factorial values or use simplification:
$$= \frac{12 \times 11 \times 10}{3 \times 2 \times 1} = 220$$
4. **Step 2: Calculate ways to choose 2 western movies from 8:**
$$\binom{8}{2} = \frac{8!}{2!(8-2)!} = \frac{8!}{2!6!}$$
Simplify:
$$= \frac{8 \times 7}{2 \times 1} = 28$$
5. **Step 3: Calculate total ways:**
Since the choices are independent, multiply the two results:
$$220 \times 28 = 6160$$
**Final answer:** There are **6160** ways to choose 3 sci-fi and 2 western movies from the store.