Logic Riddles

 

Question: The London Racetrack needs to submit its 3 fastest horses to the Kentucky Derby out of 25 horses. However, all of their information was lost and they don't know any of the horse's times. Similarly, they all look identical so they can't remember who's fastest.

They can only race 5 horses at once, so what is the fewest number of races they can conduct to find the 3 fastest horses?


Rat maze (medium)

Question: A rat is placed at the beginning of a maze and must make it to the end. There are four paths at the start that he has an equal chance of taking: path A takes 5 minutes and leads to the end, path B takes 8 minutes and leads to the start, path C takes 3 minutes and leads to the end, and path D takes 2 minutes and leads to the start.

What is the expected amount of time it will take for the rat to finish the maze?

Question: There is a party of 100 high-powered politicians. All of them are either honest or liars. You walk in knowing two things:

- At least one of them is honest.
- If you take any two politicians, at least one of them is a liar.

From this information, can you know how many are liars and how many are honest?

Question: Three gods A, B, and C are called, in no particular order, True, False, and Random. True always speaks truly, False always speaks falsely, but whether Random speaks truly or falsely is a completely random matter. Your task is to determine the identities of A, B, and C by asking three yes-no questions; each question must be put to exactly one god. The gods understand English, but will answer all questions in their own language, in which the words for yes and no are da and ja, in some order. You do not know which word means which.

What three questions can you ask?

Question: If 1+9+8=1, what is 2+8+9?