Three knights of the round table are urgently heading to a meeting with King Arthur. During the long trip, they decide to stop at an inn to regain strength. Each of them asks for a steak at the innkeeper and they press him to have the food ready in thirty minutes.
The innkeeper is faced with a problem, since he can only cook two steaks simultaneously and each one must be cooked for 10 minutes on each side so that in 20 minutes he would have cooked two of them but he would need 20 more minutes to cook the third.
How will the innkeeper cook the three steaks in 30 minutes with the limitations mentioned above?
The innkeeper places the first two fillets (say 1 and 2) and cooks them on one side. After 10 minutes, take out one of the steaks (steak 1), turn the second one and place the third one to cook. After 10 more minutes, steak 2 is fully cooked and steaks 1 and 3 are cooked on one side so that in 10 minutes you can cook them on the other side and have them all ready in 30 minutes. Easy, right?