Long Riddles

Long riddles with answers test your problem solving skills. These lengthy puzzles test your ability to piece together information and find the answer.

Red and Blue Marbles

Your friend has 100 red marbles, 100 blue marbles and 2 jars.

He proposes a game. He fills the jars with the marbles, put the two jars behind his back and tell you to pick one of them at random. You’ll then close your eyes, he’ll hand you the jar you picked, and you’ll pick a random marble from that jar.

You win if the marble you pick is blue, and you lose otherwise.

To give you the best shot at winning, your friend gives you the two jars before the game starts and says you can move the marbles around however you’d like, as long as all 200 marbles are in one of the 2 jars (that is, you can’t throw any marbles away).

How should you move the marbles around to give yourself the best chance of picking a blue marble?

Riddle Answer

Flipping Lockers

There are 1 million closed school lockers in a row, labeled 1 through 1,000,000.

You first go through and flip every locker open.

Then you go through and flip every other locker (locker 2, 4, 6, etc…). When you’re done, all the even-numbered lockers are closed.

You then go through and flip every third locker (3, 6, 9, etc…). “Flipping” mean you open it if it’s closed, and close it if it’s open. For example, as you go through this time, you close locker 3 (because it was still open after the previous run through), but you open locker 6, since you had closed it in the previous run through.

Then you go through and flip every fourth locker (4, 8, 12, etc…), then every fifth locker (5, 10, 15, etc…), then every sixth locker (6, 12, 18, etc…) and so on. At the end, you’re going through and flipping every 999,998th locker (which is just locker 999,998), then every 999,999th locker (which is just locker 999,999), and finally, every 1,000,000th locker (which is just locker 1,000,000).

At the end of this, is locker 1,000,000 open or closed?

Riddle Answer

Survival of the Sheep

There is an island filled with grass and trees and plants. The only inhabitants are 100 lions and 1 sheep.

The lions are special:

  1. They are infinitely logical, smart, and completely aware of their surroundings
  2. They can survive by just eating grass (and there is an infinite amount of grass on the island)
  3. They prefer of course to eat the sheep
  4. Their only food options are grass or sheep

Now, here’s the kicker:

  • If a lion eats a sheep he TURNS into a sheep (and could then be eaten by other lions)
  • A lion would rather eat grass all his life than be eaten by another lion (after he turned into a sheep)

You can make the following assumptions:

  1. Assume that one lion is closest to the sheep and will get to it before all others. Assume that there is never an issue with who gets to the sheep first. The issue is whether the first lion will get eaten by other lions afterwards or not
  2. The sheep cannot get away from the lion if the lion decides to eat it
  3. Do not assume anything that hasn’t been stated above

Will that one sheep get eaten or not and why?

Riddle Answer

Four Suitors

A wise king devised a contest to see who would receive the princess’ hand in marriage. The princess was put in a 50×50 foot carpeted room. Each of her four suitors was put in one corner of the room with a small box to stand on. The first one to touch the princess’ hand would be the winner and become the new king.

The rules of the test were that the contestants could not walk over the carpet, cross the carpet, or hang from anything; nor could they use anything but their body and wits. One suitor figured out a way and married the princess and became the new king.

What did he do?

Riddle Answer

Rich Merchant’s Gold Coins

A rich merchant had collected many gold coins. He did not want anybody to know about them. One day, his wife asked, “How many gold coins do we have?”

After pausing a moment, he replied, “Well! If I divide the coins into two unequal numbers, then 32 times the difference between the two numbers equals the difference between the squares of the two numbers.”

The wife looked puzzled. Can you help the merchant’s wife by finding out how many gold coins they have?

Riddle Answer