Two men play a dice game involving roll of two standard dice. Man X says that a 12 will be rolled first. Man Y says that two consecutive 7s will be rolled first. The men keep rolling until one of them wins. What is the probability that X will win ?
What's the next in the series? H, Be, F, S, Mn, Kr, In, Gd, Tl, ?
What word is pronounced the same if you take away four of its five letters?
What are the 50th, 63rd and 100th numbers in the sequence below? 4, 5, 8, 8, 9, 9, 12, 13, 13, 13, 17, 18, ...
Can you count the number of squares in the figure below?
What does a man do only once in his lifetime, but women do once a year after they are 29?
You need to move three matchsticks to form three squares. Can you do it?
How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?
What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?
What came first, the chicken or the egg?
Can you guess the name of the month by looking the below rebus ?
There is a cryptic organization called Cicada 3301 that posts challenging puzzles online, possibly to recruit codebreakers and linguists.