user
Four friends are comparing their ages. Alice is older than Bob but younger than Carol. Dave is older than Alice but younger than Bob. Who is the oldest and who is the youngest?
assistant
Carol is the oldest, and Bob is the youngest.

Here's the reasoning:

1. Alice is older than Bob but younger than Carol. This means Carol > Alice > Bob.
2. Dave is older than Alice but younger than Bob. This means Bob > Dave > Alice.
3. Comparing both sets of information, we get Carol > Alice > Bob > Dave > Alice. Since Alice appears twice, we can simplify it to Carol > Alice > Bob > Dave.
4. From this order, we can see that Carol is the oldest, and Bob is the youngest.