My friend gave me the following magic square to solve $$\begin{bmatrix}\frac23&5&?\\\frac19&?&?\\?&?&?\end{bmatrix}$$ I can solve it. Can you? You must provide logical reasoning in your answer to get the green checkmark.

Consider the following Scrabble board: We can play NO for 1 point, AI for 2 points, NOSE for 3 points etc as indicated on the right. All this obviously depends on having the correct letters on your rack (not shown). Eventually we will reach a number N such that it is impossible to score exactly ...

I posted this riddle for an unforeseen. Clue 1: Since 1935... Clue 2: An uncle always in Clue 3: Some references about the invisible hand Clue 4: Only one will get it... Clue 5: But luck is the real protagonist Who am I?

I took a word to work with me And it made me look quite stately Then afterwards, I had some tea Which improved my grunge look greatly But my caffeine brain got jumbled up And I was gasping to have some more I rushed to the kettle, The middle fell out My brain got in a pickle, And I nearly went ly...

Besides this problem I also use the following one to rise the interest of my students on the Probabilities Theory. It's a funny puzzle were the use of simple arithmetic rules doesn't work. We have to workaround a little bit to find the answer. So here it goes: The Random Family decided to go on ...

I've found this problem in my book "Riddles and reason" and after several attempts I still have no idea how to tackle it. The problem is as follows: The figure from below shows a truncated pyramid. How different ways can you go from from point $A$ to point $G$ without going through by the same v...

The answer to this puzzle is a list of seven thematically related words or proper names or phrases. Each of these is clued cryptically, and the theme is to be determined. Since the definition part of a cryptic clue would give away the theme, these cryptic clues use a family member (e.g., mom, sis...

Inspired by The five problems of the six domino tiles, where one of the tasks was to place six domino tiles so that each tile touches three others (corner / edge touches don't count). My solution there required putting domino tiles on top of each other, and the OP (not the author of the puzzle) t...

Take a number between 2001 and 2100 inclusive. Cube the digits of the number and add them together, then repeat the process with the new sum and restart the process over and over. For example if I take 2016, the next number will then be 225, then 141, then 66, then 432, then 99, then 1458, then 7...

Can you draw three squares on a piece of paper, such that they form nine distinct squares? Good luck!

What is the maximum number of triangles you can form by drawing three triangles on a piece of paper? Good luck!

I am a new user, now that I have a bit more time I would like to learn more about how to improve in solving puzzles. Most of the time when I attempt to solve a puzzle I keep using the same set of skills that I know. I saw that there is post with a collection of puzzling tools but I rarely think t...

I took a word to work with me And it made me feel quite retentive, Then when lunch came, my friends would agree, Rearranging it was quite an incentive Come home time and I reversed direction To get me to my abode, But my ire was combined As I was hit from behind And damaged my lymph node What's ...

My brother Yzarc is always trying to be clever. Today he claims that 2 equals 10w43e25s10e36n31w. Why does he say that?

Why is 4382516 the pin of my Samsung phone? Note: This is the first time I post on this stackexchange, I hope I did it right. I think this is a puzzle that you will find fun. It has a unique solution that can be found by anyone and you will know that it is the solution when you find it.

On Jeopardy, there are clues called "Before and After" which asks contestants to answer questions like Period of rest in Genesis where working parents leave toddlers SEVENTH DAY CARE CENTERS However, I'm sure this form of wordplay has a name and existed before Jeopardy. I once stumbled across a ...

I'm usually on top, or behind a bar Some sly-sounding people will throw me far So watch as I pass you by, Hurrah! I can be sweet yet cold you see And few will want to count on me What am I and can you explain all seven clues?

"See you in the morning. Make sure you're not late," my grandfather said. Then, he handed me this photo and left. I was worried I wouldn't be able to solve my grandfather's puzzle, so I immediately set my attention to it. Late into the evening, I was struggling still and thought I would need to c...