Count the number of triangles in the picture below:
A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train. How did it happen?
I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?
A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396. What is the sum of the three digits?
There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?
What is the word or phrase?
If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?
What can go up a chimney down, but can’t go down a chimney up?
There are forty elephants and they have forty-fore heads. How can this be possible?
A network of 20 x 10 squares is given to you. Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?
John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller. I called their home number and one of them picked up. I asked. 'Does John lie?' The person replied with a yes. Whom did I talk with, John or Jacob?
There is a cryptic organization called Cicada 3301 that posts challenging puzzles online, possibly to recruit codebreakers and linguists.
