A professor thinks of two consecutive numbers between 1 and 10. 'A' knows the 1st number and 'B' knows the second number A: I do not know your number. B: Nor do I know your number. A: Now I know. What are the four solutions for this?
Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.
People make me, save me, change me, raise me. What am I?
There was a strange boy who was born before his father. How can this be possible?
What am I?
You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?
What runs around the whole yard without moving?
What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?
Can you spot the hidden girl in the picture below?
See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.
What Time Should the last watch show in the below figure?
There is a cryptic organization called Cicada 3301 that posts challenging puzzles online, possibly to recruit codebreakers and linguists.