Tag Archives: Brainteasers

The lazy comrade

Algebra

Yesterday, that is, the day before I wrote this, I received the English translation of Boris Kordemsky’s “Russian Puzzles” (Matematicheskaia smekalka, which translates as ‘Math savvy’), edited by Martin Gardner. It was first published in 1956. In the first few chapters it contains many old chestnuts, sometimes disguised in a new coat. Though I am not a big fan of Martin Gardner, he did preserve the Russian atmosphere well. Many of the familiar puzzles can also be found in the works of Henry Dudeney and Sam Loyd. Alas Martin Gardner left out a series of problems towards the end related to number theory (‘too difficult for the american public’). Now that that sounds like two insults :).

A_Stiff_PullIt inspired me to make a small variation:
“I will plough this field at an average of 200 furrows a day,” Pjotr told his comrades in the Kolkhoz. And indeed he started out right away the next day. He set off relaxed; making just 100 furrows a day on the first 1/3 of the field , but he could blame some initial problems for thet. Once the initial problems were solved, he was able to plough at a speed of 200 furrows a day for the middle 1/3 of the field.
He realized that he was still lagging behind on his promise and made some small improvements, enabling him to complete the final third of the field at 300 furrows a day. At the next meeting of the kolkhoz he told with satisfaction that he had lived up to his promise. The party administrator however denied his claim:
“Tovarisj Pjotr,” he said, “I think you err.”

Who was right?

You can check your solutions here

A new puzzle is posted every Friday. You are welcome to comment on the puzzles. Solutions are added at the bottom of a puzzle after one or more weeks.

Odometer

Numbers, ,

Odometer problemThe display of the odometer in my car showed a number of five consecutive, decreasing digits. My mind wandered off. It was a nice number, of course. It was also clear what the next number with decreasing consecutive numbers would be, and how many kilometers I would have to drive. But what would be the next number that consisted of consecutive digits, and which also would be a prime number?

You can check your solutions here

61 equals 28?

Arithmetic, ,

61 is 28

Make the equation in the picture above correct. To do so, you may freely move the digits around. You may not add other stuff such as plus signs, multiplication signs, and so on.

Recently I purchased “Logic Brain Teasers”, published by Mensa. There was a puzzle on the back cover and while attempting to solve it as a family during dinner, the idea for this puzzle was born.

You can check your solution here

You are welcome to remark on the puzzle: its wording, style, level of difficulty. I love to read your solution times. Please do not spoil the fun for others by listing the solution.

I do offer my apologies that the puzzle above does not carry a christmas theme, as I had intended. I had two puzzles in mind, but in one I made an error in my calculation and for the other I had insufficient infomation on its origin.

Christmas time is something special in many parts of the world. For some, these are happy days with the family. For others, it’s just a few days off. For me, as an orthodox christian, it is a time of celebration.
Celebration, because where we humans develop irritation, dislike and even hate, God has come to offer a possibility of peace.
Celebration, becuase where we suffer poverty, He has come to share his richness with us.
Celebration, because where we suffer bondage, He has come to set us free.
Celebration, because the God, who is greater than our imagination can comprehend, chose to be born as a small and vulnerable baby.
I wish that you may enjoy the Christmas days and may experience a little bit of the peace, freedom, and richness he wishes to give us.