Which alphabet letter is a question?
Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?
A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?
What is black when you buy it, red when you use it, and gray when you throw it away?
John is looking at Jenifer, but Jenifer is looking at Jacob. John is married, but Jacob is not. Is a married person looking at an unmarried person ?
In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?
What can you hold in your right hand, but never in your left hand?
There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence. Do you know what word is that?
The square root of number 121 is "11". What is the square root of the number "12345678987654321."?
I am a prime number. The double of myself is equal to the square of me. which number am I?
What is red and smells like blue paint?
There is a cryptic organization called Cicada 3301 that posts challenging puzzles online, possibly to recruit codebreakers and linguists.
