1. **Problem:** There are 18 mathematics majors and 325 computer science majors. (a) In how many ways can two representatives be picked so that one is a mathematics major and the other is a computer science major? 2. **Formula:** To find the number of ways to pick one from each group, multiply the number of choices from each group: $$\text{Number of ways} = (\text{number of math majors}) \times (\text{number of CS majors})$$ 3. **Calculation:** $$18 \times 325 = 5850$$ 4. **Answer:** There are 5850 ways to pick two representatives, one from each major. **Explanation:** We use the multiplication principle because for each math major chosen, any of the CS majors can be chosen, so we multiply the counts.