Move 5 matchsticks to create exactly 10 squares.
Can you find both solutions?
The credits for this puzzle go to my daughter Margreet. The credits for the second solution go to Kees Krol.
As usual, you are welcome to report your solution times and comment on the solution, but please do not give away the answer – that may spoil the fun for others. I will publish the solution in one or two weeks after posting the puzzle.
You can check your solution here
What’s special about the following sentence?
I am not very adept making awesome drawings.
As usual, you are welcome to report your solution times and comment on the solution, but please do not give away the answer – that may spoil the fun for others. I will publish the solution in one or two weeks after posting the puzzle.
You can check your solution here
This week’s brain teaser comes from IitianWay, and I’d like to thank him for communicating it with me:
I have two ropes. Both are 1 meter long. Both will burn for exactly 1 hour. However, the speed with which they burn need not be evenly distributed over a rope. For example, the first 30 cm may burn in 30 seconds, while the other 70 cm takes the remaining 59,5 minute to burn.
How can I use them to measure 45 minutes?
As usual, you are most welcome to report your solution times and comment on the solution, but please do not give the answer – that may spoil the fun for others. I will publish the solution in one or two weeks after posting the puzzle.
You can check your solution here
1) Jimmy’s lemonade*
Jimmy looked at the 5 pint can with cold pineapple lemonade on the table in his garden. That would suffice for the whole summer afternoon, he hoped. He had however not counted in his four friends. Soon they came running. Jack brought a 4-pint can, Jill and Janet each came with a 2 pint can while little James had managed to obtain a 1 pint can.
How many pourings did Jimmy need to give each exactly 1 pint of pineapple lemonade? It goes without saying that his friends would critisize every superfluous pouring, as each pouring meant the spilling of some of that lovely lemonade.
About two monthe agao I posted here a listing of all frequently appearing pouring puzzles. The one above was not listed there, but I came across it in Games and Puzzles issue 50.
You can check your solution
1) Divide into equal halves*
Add 2 matches to divide the figures into two halves of equal size.
This problem comes from Ed Pegg jr, who published it as one of many problems in his column in Japan Airlines inflight magazine, Skyward. I think it is a nice example of an a-symmetric problem. When we design something, e have a natural tendency to design something symmetric. Designing something a-symmetric somehow seems much more difficult.
You can check your solution here
Here are 2 problems from Henry Dudeney:
1) New match problem**
In the illustration eighteen matches are shown arranged so that they enclose two spaces, one just twice as large as the other. Can you rearrange them (1) so as to enclose two four-sided spaces, one exactly three times as large as the other, and (2) so as to enclose two five-sided spaces, one exactly three times as large as the other? All the eighteen matches must be fairly used in each case; the two spaces must be quite detached, and there must be no loose
ends or duplicated matches.
2) The six sheep-pens**
Here is a new little puzzle with matches. It will be seen in the illustration that thirteen matches, representing a farmer’s hurdles, have been so placed that they enclose six sheep-pens all of the same size. Now, one of these hurdles was stolen, and the farmer wanted still to enclose six pens of equal size with the remaining twelve. How was he to do it? All the twelve matches must be fairly used, and there must be no duplicated matches or loose ends.
Both appeared in Dudeneys “Amusment in Mathematics”.
This is one of three reviews to be published this summer while i’m away on holiday,
This post is about metal puzzles that I received for my birthday and fathersday. My thanks go to the family members who donated them.
The metal puzzles from T.T.I.E, PO Box 62 2420 AB The Netherlands are a series of sturdy metal puzzles. They come in grey boxes, which are mostly of a standard size.
Many of the smaller ones look like standard problems, consisting of 1 twist. I was not able to find their website, zo it is probably not a very big firm.
Two of the puzzles I received are more original, they come from Eureka! 3D puzzles. The one with three rings is nice, I havent seen it before, though all the elements are very standard.
The puzzle which I christianed “Double E” is a nice one. It took it with me to the office, where my puzzle friends quickly solved it. Then I twisted them into each other again, and somehow we have been unable to separate them again.
You can find the website of the supplier at http://www.eureka-puzzle.eu/eureka, though they only sell to retailers, and dont seem to sell to individuals.
This is one of three reviews to be published this summer while I’m away on holiday,
This post is about plastic 3D jigsaw puzzles that I received for my birthday and fathersday. My thanks of course go to the family members who donated them.
Now I must confess that I dont like jigsaws puzzles. One reasons is they are way too common for my taste. Another reason is that they do not tax my brain enough: it needs diligent work, but not hard work.
But when it comes to 3D puzzles, the borderline becomes fuzzy. Ravensburg has published 3D jigsaw puzzles for I estimate over a decade. All pieces look like ordinary pieces, except they are thicker, so you can build walls and roofs with them.
On the other end of the 3d spectrum are the Japanese kumiki puzles, often beautifully made of wood, and representing several types of buildings, animals, fruit and other objects.
Somewhere in between are the plastic 3D jigsaw puzzles. I discovered them on the web, as produced by Kimzel Gmbh in Germany. They have a series of about 40 models. I ordered mine through Moenen and Mariken. This shop is in Dutch, and I can recommend their service, which was excellent.
If you live in the USA, you can order them from Amazon, where they are marketed by BePuzzled.
The number of pieces varies greatly. I have an apple of 13 pices, several of 46 pieces, and I have seen some of 90-100 pieces. Despite their name, they are not really crystal, but a sturdy plastic that looks like it. The copyright belongs to Beverley Enterprises Inc. & Jeruel Ind Co Ltd. The latter is a China based Toys and Puzzle producer, and the puzzles are produced in China. The pieces fit together really well. I guess the plastic does make them affordable, prices range from 3-20 euros.
This is one of three reviews to be published this summer while i’m away on holiday,
This post is about metal puzzles that I received for my birthday and fathersday. My thanks of course go to the family members who donated them.
The Hanayama series is a series of beautiful iron cast puzzles published by hanayame toys in Japan.
There are 2 kinds of packaging around, one is a beautiful shiny red/black cardboard box, the other a dull grey-green? cardboard box, which I dont have myself but did see on ads in the USA.
The puzzles themselves are very solid, and have varying degrees of difficulty. The manufacturer has them labeled with a number of stars, more stars meaning more difficult. Many of the puzzles have been designed by well established names in the puzzle world such as Oskar van Deventer and Nob Yoshigahara.
New puzzles seem to be published regularly, and can be mail ordered at several places:
They have varying degrees of difficulty, 1-5, and come without a solution, though you may try the generally know video sites if you are completely stuck. I now have one of the rings, the cast duet and the cast quartet, and probably one or more others, and I’m very satisfied with them. There must be somewhere between 50 and a 100 of them by now,
IF
8 x 2 = 46416
6 + 3 = 23618
15 : 3 = 513545
9 – 3 = 38127
Then what is :
12 x 4 =?
I am very much interested in your solution times, and you are welcome to make remarks, and discuss alternatives. Pointing out alternative solutions is also welcome, as they point out possible problems in the brain teasers, but please dont mention solutions and leave others the fun to solve them too.
If you are puzzled, we have a solution for you.
justpuzzles 