Monthly Archives: October 2013

Matchsticks – make 3 squares

1) Make 3 squares*
Matches - 3 squares exercise
Move 2 matches to make 3 squares of equal size.

This problem comes from J.A.H. Hunter

You can check your solution here

Did you know?
Farm-Fresh_brainRecent research shows that learning new skills keeps an aging mind sharp.
Lead researcher Denise Park of the University of Texas:
It seems it is not enough just to get out and do something—it is important to get out and do something that is unfamiliar and mentally challenging, and that provides broad stimulation mentally and socially. When you are inside your comfort zone you may be outside of the enhancement zone.


1000px-Stub_surgeons.svgOn a dark night a car with 2 people raced along a narrow road. Heavy rainfall left the driver with bad visibility, and the card crashed against a tree when the driver lost control.
Police quickly discovered that the father was dead, but the passenger, his son, was still alive though injured and in critical condition. An ambulance raced the son to the hospital. The surgeon, seeing the patient, cried out:
“Oh no, he is my son!”


As always, you are welcome to post your solution times.

If you solved it, you can check your solution


A Park puzzle has only two rules:
1) Every row, column and park has exactly 1 tree;
2) Trees are not adjacent horizontally, vertically or diagonally.

1) The stats*
Parks - stats - exercise

2) parks 7×7*
Parks 7x7 2013-09-10 exercise

You can check your solution here and

Did you know?
My current customer has the nice habit of allowing its employees a certain amount of freedom. It aint as much as Google’s former 20% free time, but it does offer facilities such as posting reflective sayings. One I came across is:

If you think adventure is dangerous, try routine. It’s lethal. (Paulo Coelho)

This may be not be literally true of the body, but I believe it’s certainly true of the mind. Brains which do not regularly encounter new challenges, develop less well when young and detoriate faster when old.

One thing I consciously try to do is presenting new puzzles. And not just new puzzles, but also present a new type of puzzle. This means your brain has to start afresh with a new problem. You have to figure out new ways to tackle this challenge.
By presenting several puzzles of the same new type your brain has a chance not only to discover HOW to solve them, but also to let these ways reach the conscious state. You realize what the new tricks are with which you can solve these problems. And that is an important element of acquiring new skills (and I suspect for your brain an important part of creating new neural connections)


There is a well known family game where one person takes an object in mind, and the rest of the company may ask yes/no questions and have to guess what it is.

A: OK, I’ve got something in mind
B: Is it something I can touch?
A: No.
B: So it is something abstract?
A: Hm, no
C: Is it something I can hear?
A: No
D: Is it something I can see?
A: Yes!
B: Is it inside the house?
A: No
C: Can it always be seen?
A: No
D: Just on certain days?
A: Question not clear, but probably no.
and so on.
(btw, if you want to know what A has in mind, you can ask me yes/no questions at the bottom of this page)

This kind of game consists of a series of puzzles. There is a variant, in which baffling stories are presented, and people may ask yes/no questions to explain the situation.

Exif_JPEG_PICTUREWell known examples are:
A) A man goes down with the elevator everyday. When he returns from work, he goes up half way, and takes the stairs. Unless it rains, then he goes up all the way.
B) A man is lying in a meadow. He is dead. Besides him there is a white package.
c) A man walks into a saloon. The bartender pulls his gun at the man. The man says: “thank you” and leaves the saloon.
I first heard these puzzles when I was a teenager, and you can find the solutions on several places on the web.

For those who are interested in this kind of puzzle, Paulo Sloane runs a forum with this kind of puzles at He is also the author of the book “Lateral thinking puzzlers”.