BrainDen.com - Brain Teasers

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Showing content with the highest reputation since 07/12/19 in all areas

1. 2 points

## Harder hats on deathrow version

I assume that they also all get the clue that their numbers are unique.
2. 2 points

3. 1 point

## Has anyone done a puzzle post?

Hi all, I've created a puzzle based game at PuzzlePost.uk that can be sent as a gift in the post - it might be useful for those who haven't been able to see friends and family for a while. It contains a range of puzzles to test various different aspects of your thinking. I hope you like it. Thanks, Will
4. 1 point

## 10201 poker cases and 2 scales

Hi, this is a riddle I just created. Sorry for my broken English, it's not my native language. There are two version of almost the same idea. The 1st one is purest, but the second one is more tricky. I think it's quite difficult to solve, but there is no need for any mathemical knowledge. First version of the riddle A poker manufacturer has created 10201 cases each containing 100 chips. (Note: 10201=101*101) 10200 of these cases are perfect and each of their chips weighs 10g. One of these cases is defective and its 100 chips weigh 11g each. In order to determine which of the 10201 cases is defective, the manufacturer has two scales at his disposal: A traditional, high-precision scale that can hold tons. An electronic kitchen scale that displays the weight with a precision of 2g and can hold no more than 100g. How can the manufacturer determine the defective case using only 2 times each of the 2 scales? Second version of the riddle A poker manufacturer has created 41010 cases each containing 100 chips. 41009 of these cases are perfect and each of their chips weighs 10g. One of these cases is defective and its 100 chips weigh 11g each. In order to determine which of the 41010 cases is defective, the manufacturer has two scales at his disposal: A traditional, high-precision scale that can hold tons. An electronic kitchen scale that displays the weight with a precision of 1g and can hold no more than 100g. How can the manufacturer determine the defective case using only 2 times each of the 2 scales?
5. 1 point

## Two boys problem

Hi Nemesis. As it has been verified that one of the two dogs is a male, the only probability for the other also being a male is that both are males, as given by the remaining three equally likely possibilities (1,2,3). As both 2 and 3 are invalid, 1 is the only valid result.
6. 1 point

## Groundhog in a Hole - Yet Again

You got it. Well done. I'll post my solutions later.
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9. 1 point

## Crocodile Sophism

Crocodile Sophism - Back to the Paradoxes A slim crocodile living in Nile took a child. Mother begged to give him back. The crocodile could not only talk, he was also a great sophist, and so he stated: "If you guess (Edited: predict the fate = guess correctly), what I will do with him, I will return him. However, if you don't guess his fate I'll eat him." What statement shall the mother make to save her child (what about a vicious circle ...)?
10. 1 point

## Poisonous apples

There are two bowls that you and a challenger must eat from. After flipping a coin you were selected to pick the bowl that each would eat from. In the first bowl there are three out of five poisonous apples. In the second bowl, there are two out of five poisonous apples. Whoever eats from the first bowl must eat two apples at random from the bowl. Whoever eats from the second bowl must eat three random apples from the second bowl. Which bowl should you pick to eat?
11. 1 point

## Triangle

Form a "Triangle" With 10 blocks in its top row, 9 blocks in the next row, etc., until the bottom row has one block. Each row is centered below the row above it. Color the blocks in the top row red, white, or green (or any three colors of your choosing) in any way. Use these two rules to color the remaining rows of the triangle: - If two consecutive blocks in a row have the same color, the block between them in the row below has the same color - If two consecutive blocks in a row have different colors, the block between them in the row below has the third color Tell how you can always predict the color of the bottom block after seeing only the top row (and not constructing the intermediate rows) PROVE your answer.
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13. 1 point

## Hats on a death row!! One of my favorites puzzles!

Revolt. The king is totally corrupt. The concept of justice is perverted. He doesn't deserve to be king. When everyone is lined up, everybody jump the guards and fight your way out. It is better too die on your feet than live on your knees.
14. 1 point

LEGEND
15. 1 point

## What Am I?

The letter Y?
16. 1 point

## Walking, running, driving, waiting

With a tip of the hat to @BMAD for his interesting puzzle. For your amusement, here's an interesting spin on this genre: One night you encounter a two-hour traffic delay due to an accident (the tow truck had difficulty clearing the road.) So, for a time interval 13 of two hours you were constrained to travel at 0 mph. You called home and said, sorry dear, but I'll be two hours late getting home. The next night, for some unimaginable reason, you were also constrained to travel part of the way at 0 mph, this time for a distance of one inch. What do you say now when you call home?
17. 1 point

## Crazy Circle Illusion!

Crazy Circle Illusion!
18. 1 point

## I'm not a rebellious missionary

Right on, PG, and glad you like it. This one I think I'll keep in a Sundae Best collection.
19. 1 point
20. 1 point
I have just created Homework Help forum. I have also started the first topic to list all members willing to help. Read the rules and feel free to ask questions and help others to find solutions/answers. Enjoy!
21. -1 points

## What Am I?

electricity double letters
22. -1 points

Electricity
23. -1 points

## Hard Riddle.

What cannot move but can travel?
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