## Problem Definition

### Firefighter

**Situation:**

A firefighter stood on the middle rung of a ladder, spraying water on a burning house. He then climbed up 6 rungs before the heat of the flames caused him to come down 10 rungs. After some minutes he was able to climb 18 rungs to the very top of the ladder.

**Question:**

How many rungs did the ladder have?

### Bartender

**Situation:**

There are two twin old men that go into the same bar every day. The bartender at the bar hates one of the twins, but there is only one way he could tell the difference between them: The one that he hates drinks very slowly and the one that he likes drinks fast.

One day the bartender decides to kill the one that he hates. So when they came in that day he put the same amount of the drink in their cups, the same amount of ice, and the same amount of poison. When they are both done with their drinks the one that the bartender hates dies, but the one he likes lives.

**Question:**

How is this?

### Hats

**Situation:**

There are 4 people sitting in a row, trying to win a riddle.

- The one in front was wearing a red hat.
- The second from the front was wearing a blue hat.
- The third from the front was wearing a red hat.
- The last was wearing a blue hat and is blind-folded.

Each of them was informed that they are all wearing a hat, the last person is blind-folded and that there are 2 red and 2 blue hats. They can only see the persons in front of them and are not allowed to turn around and see behind them.

**Question:**

The one who guesses the color of his hat wins the prize. Who is it?