I can write cow in 13 letters. Can You?
What do you think with the below Picture ?
What has hands, but can’t clap?
What has a bottom at the top?
What has one eye, but can’t see?
10+10 and 11+11 can give you the same answer. Explain how?
What can go up a chimney down, but can’t go down a chimney up?
Forwards I am heavy, backward I am not. What am I?
What's the only room from which no one can enter or leave
Prove that twice of ten is the same as twice of eleven.
What is the coolest letter in the alphabet?
There is a cryptic organization called Cicada 3301 that posts challenging puzzles online, possibly to recruit codebreakers and linguists.