1) puzzle 1****/*****
What is next in the sequence 1, 2, 3, 8, 15, 48, 105, 384?
2) puzzle 2****/*****
What is next after 1, 2, 3, 4, 10, 18, 28, 80, 162, 280, 880?
If you are baffled, you can find the solutions here.
Bongard dates (3)
In 1967 the Russian scientist M.M. Bongard published a book containing 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 conforms to a certain rule. Each box on the right contradicts this rule. Your task, of course, is to figure out the rule.
1)Bongard problem dates 5***/*****
2)Bongard problem dates 6****/*****
The original Bongard problems were geometrical and thus, in theory, culture free. These dates are western dates, and thus not culture independent. I have used the Italian/Dutch format. The 2-weekly puzzle column in the Guardian in the past already expanded the scope from geometry to language, but as far as I know the dates are a new territory. During my recent visit to Burkina Faso I wrote up 12 problems, so I have enough to trouble you the first half of 2020.
New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solutions here.
Happy puzzling!
Masyu
Alex Bello’s bi-weekly puzzle column at The Guardian wrote about Masyu puzzles.
More about these puzzles:
* https://krazydad.com/masyu/ – Krazy Dad has hundreds of puzzles/
* https://www.kakuro-online.com/masyu/ – contains both puzzles, a generator and a solver
Bongard letters (1)
In 1967 the Russian scientist M.M. Bongard published a book containing 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 conforms to a certain rule. Each box on the right contradicts this rule. Your task, of course, is to figure out the rule.
1)Bongard problem letters 1*/*****
2)Bongard problem letters 2**/*****
Though I’m in the midst of a series Bongard problems on Dates and times, I throw in a couple on letters just for a change.
New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solutions here and here
Happy puzzling!
Five five’s
Some of you may know the problem to make all the numbers from 1 to 20 with four fours.
I wrote about it here. It may come as a surprise to you that it is possible to make all the numbers from 0 to 100.
Today’s problem is to make all numbers from 0 to 20 using exactly five fives. For example:
(5*5 – 5*5) / 5 = 0
You can find my solutions here.
Squirrels go nuts
When I returned from Burkina Faso early January, my wife presented me with a copy of Smart Game’s new “Squirrels go Nuts!” puzzle.
I already had several of Smart Games puzzles, such as “IQ link” and “IQ Fit”, and they usually provide a decent amount of puzzles, starting easy and gradually toughening. This one is no different.
The puzzle consists of a tray with four holes, and four squirrels who have to drop their acorn into one of the four holes. Your task is to slide the squirrels over the board so that the acorns are dropped into a hole.
The puzzle comes with a booklet with 60 problems, and you may wish to skip the first half of them – personally I found them ridiculously easy, and no, I’m not a super genius.
Bongard dates (2)
In 1967 the Russian scientist M.M. Bongard published a book containing 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 conforms to a certain rule. Each box on the right contradicts this rule. Your task, of course, is to figure out the rule.
1)Bongard problem dates 3*/*****
2)Bongard problem dates 4*/*****
The original Bongard problems were geometrical and thus, in theory, culture free. These dates are western dates, and thus not culture independent. I have used the Italian/Dutch format. The 2-weekly puzzle column in the Guardian in the past already expanded the scope from geometry to language, but as far as I know the dates are a new territory. During my recent visit to Burkina Faso I wrote up 12 problems, so I have enough to trouble you the first half of 2020.
New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solutions here
Happy puzzling!
Three cubes
In the picture above, when we calculate the sum of the three cubes on the left side, we see that two of the digits are present in the sum.
There are no 2-digit numbers which are equal to the sum of the squares of their digits.
There are 3-digit numbers which are equal to the sum of their third powers. Which are they?
Bongard dates (1)
In 1967 the Russian scientist M.M. Bongard published a book containing 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 conforms to a certain rule. Each box on the right contradicts this rule. Your task, of course, is to figure out the rule.
1)Bongard problem dates 1*/*****
2)Bongard problem dates 2*/*****
The original Bongard problems were geometrical and thus, in theory, culture free. These dates are western dates, and thus not culture independent. I have used the Italian/Dutch format. The 2-weekly puzzle column in the Guardian in the past already expanded the scope from geometry to language, and the dates are a new territory. During my recent visit to Burkina Faso I wrote up 12 problems, so I have enough to trouble you the first half of 2020.
New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solutions here and here
Happy puzzling!
2020
It’s 2020, a new year! Here are a couple of 2020 related brainteasers:
1) 0-9!**/*****
Make each and every of the numbers 0-9 by combining the four digits 2, 0, 2, and 0 with arithmetic and mathematical operators. For example 0*(2+2)+0=0
2) two different digits**/*****
The year 2020 has only 2 different digits, 0 and 2. How many of those years do we have in this centur?
3) 0-9!**/*****
And as a sequel on 2): how many such years are there in this millennium?
You can check your solutions here
New puzzles are published at least twice a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars.
justpuzzles 