Can you form a 4x7 rectangle from every tetromino, tromino and domino? There are 5 different tetrominoes, 2 trominoes and 1 domino. Can you find different arrangements that are not mirrors/rotations of each other?

What is the minimum number of X pentominoes you need to cover every cell of an 8x8 grid? Pentominoes may overlap each other and sit outside the boundary of the grid. An X pentomino looks like this:

What is the minimum number of W pentominoes you need to cover every cell of an 8x8 grid? Pentominoes may overlap each other and sit outside the boundary of the grid. They can also be rotated in any way. An W pentomino looks like this: Here is a similar puzzle with X pentominoes: Covering an 8x...

Consider the numerical sequence $$800,1600,4800,6400,12000,6400, \cdots.$$ Is there any pattern involved in this sequence? I am very curious to know that. Any help will be highly appreciated. Thank you very much.

My beginning is a time for a leader to lead. My middle is a type of insect seed. My end is a talk that’s shorter than a screed. I increased a problem that was losing all its speed. What am I?

During school I studied some cryptography and creating a story about it, I was able to create this riddle! I hope you like it <3 In one country all the inhabitants are thieves. Items cannot be transported on the street without being stolen immediately. The only way, for example, ...

You requested the password for a super secret cookbook and received an SMS with the following content: 77733666688833 2555555 777772222337777 2663 777337555222233 84433 6688622337777777 9444844 3444444487777 8666 777766622233333 666 777 88 4 55 444 3 77 6 333 9999 99 4 333 444 888 33 8 44 777 33...

I did the Norwegian Mensa web IQ test at http://test.mensa.no/. I have tried to solve this exercise for a day, but with no luck. I'm still puzzled by this exercise.

there. In the following picture is a puzzling question from a primary school math exercise booklet for selective high school exams in Australia. I don't think enough information is provided to solve this question but there may be something I missed out. Thank you for your help.

So I am new here and haven't heard anything about these puzzles being used anywhere else. There are a lot of nice cryptic crosswords and similar puzzles created by people here that would do very well in other places. I am particularly thinking of a trivia site I frequent, it possibly could be a g...

Puzzle from my good friend and fellow Sporcle user, AuroraIllumina! Eight children are riding the carousel: four girls (Anna, Beth, Claire, Diana), and four boys (Eric, Frank, George, Henry). It is your job to determine which position each of them is sitting in. Rules: The two people wit...

You have a beaker containing 100ml of water, standing on a digital scale. The scale has been calibrated to the beaker so that it shows only the weight of the water, which is exactly 100.0 grams. The beaker is perfectly cylindrical, and the depth of the water in it is exactly 5 cm. You have a pen...

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. important... please sovle .....................

Find the missing number 56784 = 4 11111 = 0 72348 = 3 88652 = 5 88811 = 6 75213 = 0 65465 = 3 62257 = ? I found this quiz in an archive of our company's internal blog. There is no solution provided, nor is there a hint who the author might be. I could not find a solution myself and I am not s...

Which reptile eats its skin after sunbathing? This is an easier "showpiece" how (some of) my puzzles work. The others are more complex. The answer will be revealed if no correct answer arrives within 48 hours.

Can some body please solve this

Someone, or something, has been abducting members of your community! Though no deaths are reported, recovered victims are said to have suffered from a severe, albeit temporary, case of what could best be described as "dancing fever" and little to no recollection of prior events (apparently due to...

I live in Britain's smallest historic county - Clackmannanshire, in Scotland. It is often referred to locally as the "The Wee County." "The Wee County" appears in this puzzle I created, but the idea is to work out where the letters fit into the partially completed circular sequence (ignore case...