A swan sits at the center of a perfectly circular lake. At an edge of the lake stands a ravenous monster waiting to devour the swan. The monster can not enter the water, but it will run around the circumference of the lake to try to catch the swan as soon as it reaches the shore. The monster moves at 4 times the speed of the swan, and it will always move in the direction along the shore that brings it closer to the swan the quickest. Both the swan and the the monster can change directions in an instant.
The swan knows that if it can reach the lake's shore without the monster right on top of it, it can instantly escape into the surrounding forest.
How can the swan successfully escape?
You can see it everyday, But cannot touch it at will. What is it?
How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?
I ask Joseph to pick any 5 cards out of a deck with no Jokers.
He can inspect then shuffle the deck before picking any five cards. He picks out 5 cards then hands them to me (Jack can't see any of this). I look at the cards and I pick 1 card out and give it back to Joseph. I then arrange the other four cards in a special way, and give those 4 cards all face down, and in a neat pile, to Jack.
Jack looks at the 4 cards i gave him, and says out loud which card Joseph is holding (suit and number). How?
The solution uses pure logic, not sleight of hand. All Jack needs to know is the order of the cards and what is on their face, nothing more.
A prisoner is told: "If you tell a lie, we will hang you and if you tell the truth, we will shoot you." What did the prisoner say to save himself?
I have teeth but i don't bite. Who Am I ?
f you were running a race, and you passed the person in 2nd place, what place would you be in now?
What is both possible and impossible at the same time?
How much will a 38° angle measure when looked at under a microscope that magnifies ten times?
I am a ten letters word
The first four letters have the power to rule,
Next, four-letter can be eaten.
The next three-letter represents a lady.
I can fly as well
what am I looking for?
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.