Today I proudly present our first free e-book!
This e-book contains 30 unique number puzzles. The puzzles range from brainteasers to futoshiki puzzles and matchsticks problems. Some puzzle types have been published on this blog, others are new.
You can download this e-book here
1) Make 3 squares*
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?
Recent 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.
On 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!”
Explain.
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*
2) parks 7×7*
You can check your solution here and
here.
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.
Example:
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.
Well 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 www.lateralpuzzles.com. He is also the author of the book “Lateral thinking puzzlers”.
1) Complete the alphabet*
ACDEHIMNOTU
BFGJKLPQRSVWXY
In which row does the letter Z go?
If you solved it, we have the solution
This brainteaser was published in the British magazine “Games and Puzzles”.
1) Circles**
Which code belongs at the question mark?
If you wish, you can peek at a hint
I have long suspected that there is a strong connection between mathematics and puzzles. Proving such a relation according to the scientific standards is of course another matter. It was nice to read that a study by the University of Chicago found that puzzle play helps boost Learning Math-Related skills in children between ages 2 and 4.
1) 3×3
Every row and column adds up to 50
Complete the square with the indicated numbers – those who have been given are already crossed out for you.
2) 4×4
Every row and column adds up to 50
3) 5×5
Every row and column adds up to 100.
This type of puzzle was published in Cijfervaria, a publication of Sanders Puzzelboeken. As I write this, they just published issue 5. Though I missed issue 4, I see they regularly publish Soduko variants, Binairo, Triairo, hitori, and battle ship.
You can check your solution here, here and
here.
Did you know…
Learning new tasks saves brain cells – even if these tasks are more or less similar to already known tasks.
Using exactly four fours, create the numbers 0-30. You may use the usual mathematical operands, but not squaring, as this requires a number 2. You may use brackets.
Example: (4+4)-(4+4)=0
As always, please don’t publish your solutions. Solutions can be found after 1-2 weeks on the solution page for those who want to check their solutions, or for those who are really stuck.
But scrolling is much easier, and really spoils the fun for others.
I am very much interested in your solution times, and I welcome your remarks and criticisms. Pointing out alternative solutions is also welcome, as they point out possible problems in the brain teasers.
If you are puzzled, we have a solution for you.
This puzzle has a long history. When I still was a teenager, my father challenged me to make all numbers 0-20 using the digit 4 exactly 4 times. Recently I shared this puzzle with some fellow consultants. Kees Krol arrived at the office one morning and announced he had extended the range all the way to 30. 🙂
1) 5×12 nr 1
1) 5 x 12 rectangle*
This 5×12 rectangle consists of the twelve different figures of 5 squares each. The original borders have been removed.
Each figure contains the letters A, B, C, D and E exectly once.
Can you find restore the borders between the twelve figures?
For those of you who are not familiar with them, here are the 12 possible pentominoes, or possible figures of 5 squares.
This type of puzzle was, as far as I know, first published in the British magazine Games and Puzzles, issue no 50, july 1976.
There is a type of puzzle where all bones from the double 6 set are laid down in a 7×8 square. Sometimes that type of puzzle is called dominosa. You can find a couple of them on my homepage, the domino plaza. Because the type of puzzle is very similar, I have christened this type of puzzle pentominosa.
2) 5 x 12 rectangle*
3) 5 x 12 rectangle**
You can check your solutions at here, here and here.
Please do not list the solution(s). In all other respects, I welcome discussion, listing alternative solutions, and I espoecially welcome your solution times, as that helps me to get an impression of the difficulty.
justpuzzles 