Answer: One man murdered the other to eat him. However, since one was murdered and didn't starve, the murderer didn't win. So eventually, when the "food" runs out, he eventually starves.
Answer: Flip the first switch and leave it on for a while. Turn it off. Then, flip the second switch, and leave it on. Keep the third switch off. Enter the room. If the bulb's off, but warm, it's the first switch. If the bulb is on, it's the second. If the bulb is off and cool, it's the third.