I had to tile the floor of a room which was to 2 meters long and 2 meters wide. I had boards of 20 cm wide and either 1.60 or 1.80 meter long. How many boards do I have to saw so that I can cover the entire floor?
You can check your solutions here
I had to tile the floor of a room which was to 2 meters long and 2 meters wide. I had boards of 20 cm wide and either 1.60 or 1.80 meter long. How many boards do I have to saw so that I can cover the entire floor?
You can check your solutions here
Before you are four cards on the table. The front side has an ‘A’ or a ‘B’ on it. The back has a ‘1’ or a ‘2’ on it. As you can see, two cards show their front side, and the other two cards show their back side.
A friend of mine thinks that on the back of every card with a ‘B’ there is a ‘2’.
Which card(s) do you turn to test his hypothesis?
This is not an original problem, and the source is unknown to me. I guess it is from somewhere in the twentieth century. I was recently reminded of it when thumbing through James Fixx “More games for the superintelligent”, a mensa publication. I hope to get back to this puzzle in a later post.
You can check your solutions here
The free Dutch daily newspaper Metro recently – I think it was in september – published a new type of puzzle calles tectonics.
The puzzle area usually is a rectangle, for example 4×5, which is subdivided into areas of size 1 to 5. An area of size 1 contains just the number 1, an area of size 2 contains the numbers 1 and 2, and so on, until an area of size 5 which contains the numbers 1, 2, 3, 4 and 5 exactly once.
A second rule is that the same number may never be adjacent: not horizontally, not vertically, and not diagonally.
Note that there is no rule that a number may appear just once in a row or column.
A complete filled tectonic may look like:
The puzzles in Metro are designed by Denksport, the largest puzzle publisher in the Netherlands. In the magazine shop I discovered a magazine with these puzzles.
Tectonic puzzle booklet can be ordered here. I think the order page is only in Dutch, and I’m not sure if you can mail order from abroad.
You can check your solutions here, here, and here.
The publisher claims that these puzzles are a new international rage. That may well be true, but a quick search on “tectonic puzzles” turned up just puzzles on plate tectonics.
The Russian scientist M.M. Bongard published a book in 1967 that contains 100 problems. Each problem consists of 12 small boxes: six boxes on the left and six on the right. Each of the six boxes on the left conform to a certain rule. Each and every box on the right contradicts this rule. Your task, of course, is to figure out the rule.
You can check your solutions here
You can find more Bongard problems at Harry Foundalis site, and I intend to publish more problems in the future.