Three lords enter a hotel. The receptionist at the front desk tells them that one room is 10 pounds so each of the gentlemen pay – 30 pounds altogether.

When the porter wants to bring the luggage to lord’s rooms, hotel director rushes in to tell him that it was supposed to be only 25 pounds for the three rooms and he gives him the extra 5 pounds to return them to lords.

The porter had no idea know how to divide 5 pounds between 3 gentlemen so he gave one pound to each of them and kept the remaining 2.

Each lord paid 9 pounds (10 originally and got one back). 3×9=27. The porter kept two pounds. 27+2=29. What happened with the remaining one pound?

Evil warlock doesn’t like dwarfs so he chooses four of them and buries them into the ground so that only their heads are above surface. Dwarfs can’t move at all and they can look only forward.

They’re buried in a line and one of them is separated by a wall. They are all facing the same direction: last dwarf sees two heads of his friends and a wall. Second last sees only one had and a wall. Second dwarf sees only the wall and first is looking to the distance where he can see nothing interesting though.

Warlock explains the situation to dwarfs and tells them that he has placed hats on their heads – two blue hats and two red ones. One of the dwarfs is supposed to say what color is the hat he is wearing. If he says the right color warlock will dig them out immediately. If he says something else all of them will stay there till the end…

How will dwarfs solve this problem?