Fill in the nine X spots in the following equation using each of 1, 2, ..., 9 exactly once, so that the equation is satisfied. The XX in the denominator denotes concatenation of two digits. $$ \frac{X}{XX} + \frac{X}{XX} + \frac{X}{XX} = 1 $$ Source: the problem for January 1 on Mathematics Cale...

The puzzle is as follows: The alternatives given are: 8 movements 9 movements 5 movements 6 movements This puzzle doesn't have an official answer. But I'm getting 9. But I don't know exactly if my answer is right or reasonable, Does it exist a criteria on what to do to solve these kinds of puz...

I got [prefix] [suffix] [infix] from washing the [whole]. P.S. I [infix] the [whole]. The note above, when the gaps are filled, will be a grammatical and reasonable note. What is the note?

Given the 3 containers - a cylinder with base radius 1 and height 1, a box with side 2 height 1 and half sphere with radius 1 in the middle, a box with side 2 height 1 and cone with base radius 1 and height 1 in the middle. The cylinder is full with water. By moving the water between the containe...

What do these three towns have in common? "Dublin", "Blackpool", "Chernobyl".

The puzzle is as follows: A dairy plant in Milwaukee is well known for its yoghurt. However during the quality control a factory worker forgot to bring a set of adequate vessels to measure the required amount of yoghurt to be sent to the lab. In his set, he has a container filled with 14 liters ...

The puzzle is as follows: The figure from below shows a lock mechanism used to store sensitive data microfilms from a certain lab. This mechanism is magnetic and consists in numbered buttons which allow them to be moved. The only valid movements are non-rotating exchanges between two contiguo...

Here are 6 places I visited in 2008: Now tell me, where was the Sun?

Since it's the 20th of January, perhaps we can demonstrate an orderly transition from TRUMP to BIDEN? There are eight steps to get there and all words are found in the World Scrabble dictionary. One of them is not an everyday word but shouldn't be too unusual as it is used in anatomy (and weigh...

I am posting an interesting problem which I find in my local magazine.At first sight, I think this will be an easy one . But I am wrong. Can anyone help me to find some logical deducation from this question? Thanks in advance The question is as follows: There are 2 thieves shub and tush and they ...

My friend said to me: “In February of the year 1970 at 1:12 AM Ma turned 18. Ma turned 34 in February of the year 2002 at 2:16 AM. How is this possible?” “And yes. Same Ma!” he ended with that.

Gaby numbers her 21 students with the primes between 11 and 97. She now asks them to sit around a circle making sure that any two of them sitting next to each other have either their tens or units digit equal. In how many essentially different ways can they so sit?

If I have a multiple choice question where $\int_ {e} ^ {2e} \frac {x} {\ln(x)} dx $ is equal to: a) 6.55... b) 7.28... c) 7.93... d) 7.96... e) 8.10... f) 10.10... the ... means that there is another numbers or not. What is the exact value of this integral? What's the fastest way to find the ri...

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the eleventh puzzle in this series! For more information about the series, see the first puzzle and the introduction. Enjoy!               Can you ascend this puzzle and reach the top? Google ...

All sides of a triangle T1 are shorter than the shortest side of a triangle T2. Is it always possible to put triangle T1 completely inside triangle T2?

I received a bag of wooden pieces, but cannot figure out what the puzzle is supposed to be. I've tried several burr options and several Alketruse puzzles, but cannot find the correct configuration. All pieces are the same. There are 23 total (not sure how many it should be because it could be ...

Fill in the numbers 1 through 9 in the 9 empty cells (each number appears exactly once) to make the row and column expressions equal to the number at the end of the row or column. Regular math operations rules apply; multiplication and division before addition and subtraction. A solid B means it ...

Let's have a 10x10 grid. We want to create a Sudoku in which, in each row, the pairs (a+b), (c+d), (e+f), (g+h), (i+j) add to one of the following numbers: 7, 9, 11, 13, or 15. Can you construct a complete 10x10 Sudoku fulfilling this requirement? NOTE:The numbers in the grid are there for clarif...