Nonsense

Charles Lutwidge Dodgson was a mathematician in the nineteenth century. He was also a writer, photographer, and deacon. His pen name was Lewis Carroll.

His talent was playing with logic. Here are a few extracts from his book, Alice in Wonderland. 

     "Take some more tea," the March Hare said to Alice, very earnestly.
     "I've had nothing yet," Alice replied in an offended tone: "so I can't take more."
     "You mean you can't take less," said the Hatter. "It's very easy to take more than nothing." (Chapter VII).

Do you agree with Alice or the Hatter?

Here's some more:

About the ordered execution of the Cheshire cat, who only had a head at this point in the book:


"The executioner's argument was, that you couldn't cut off a head unless there was a body to cut it off from: that he had never had to do such a thing before, and he wasn't going to begin at his time of life.
The King's argument was that anything that had a head could be beheaded, and you weren't to talk nonsense. "

Again, who do you agree with?

Wonky Scale...

A farmer badly in need of money has decided to sell walnuts. He has a brick that weighs exactly 1 kilogram and a wonky lever balance: the distances are different. A customer comes and asks for 2 kg of walnuts.

The farmer thinks that if he puts the the weight in the left pan and measures out walnuts to balance it out, then switches the walnuts and the weight, and adds the two amounts of walnuts, he'll have the two kilograms.
Is he right?

If not, then how is it possible to measure the two kilograms?

Happy Birthday

"The day before yesterday I was 10 years old, and next year I'll turn 13."

Could this be the truth?
If yes, then how?

Lift

A person walks into an elevator on the first floor, goes up eleven floors, gets out, and walks up four flights of stairs. This person does this every day. Why?

The lift goes up to the top of the building (say 20 floors), and the person isn't crazy, or badly in need of exercise. 

The answer will be at answersdiscarded.blogspot.com someday.

Counterfeit Coins

You have nine identical coins. One of them is counterfeit. The counterfeit one is a tiny bit lighter than the normal ones. 

In two weightings (see picture), how can you figure out which one is counterfeit?

The answer will soon be at answersdiscarded.blogspot.com.

Wise People

On a distant planet, far across the galaxies, a mighty ruler decided to test her wise people to find out which one of them was the wisest. She invited them to her planet,  and offered them wine and food.  The wise people, whose talents were much unappreciated,  had not seen so much food in all of their lives, and were soon sound asleep.  When the wise people woke up, they all saw that everyone's faces were colored green, but they could not see their own faces. They all immediately started laughing, and so did the ruler, quietly laughing behind her secret spot under a table loaded with dessert.
But then one stopped, and then another.
They all gradually stopped laughing, realizing that they, too must have paint on their faces.
The ruler named the first one to stop her prime minister.

Question: how did the wise people find out that they, too had been colored green?
Hint: try deciding on a number of wise people.

The answer is at answersdiscarded.blogspot.com.

PLEASE THINK ABOUT IT BEFORE YOU LOOK IT UP.

Knights and Knaves (starting easy)

     I think that this may be my favourite type of math/logic riddle.  In a world where there are only knights and knaves...

Knights can only tell the truth.  Knaves can only lie.

     You are on an island with two towns, walking  along a road. One town is where all the knaves live, and the other is where all the knights live. You have to post a letter to your friend, but there is only one post office, and it's in the knights' town.
     You have come to a fork: one road leads to the knaves' town and the other to the knights' town. You see a man sitting at the fork, but you do not know whether he is a knight or a knave.  On this peculiar island, you are always allowed to ask one question to another person.  You have to ask him a question which determines which town is the knights' town.  Remember: you do not know whether he is a knight or a knave.


This is one of the easier questions of this type. Again, the answer is at discardedlogic.blogspot.com, answer number 5.  PLEASE TRY TO FIND THE ANSWER before looking it up. (!)

Choosing a computer

In a very peculiar shop, there are three computers, one each of three types:
-American computers, which always answer any questions truthfully,
-Chinese computers, which always lie,
-Russian computers, which sometimes lie, and sometimes tell the truth.

You want a computer that can answer yes/no questions, and you don't care if it's an American computer or a Chinese one. You do not, however want a Russian one.
The biggest problem with these computers is that they are exactly alike on the outside. The shopkeeper tells you that you are allowed to ask ONE question to ONE computer.

In this one question, you have to find out whether or not this computer is Russian.

What is the question?

To find the answer, go to discardedlogic.blogspot.com, answer number 4, where there may be the answer to the question of the question. (It depends on when you look and when I put the answer up).

Zmei Gorynych

Ivan-Tsarevitch: A charming young prince, whose strength and bravery are known to every simpleton in the tsardom.
Zmei Gorynych: A three-headed dragon-serpent who/which dies in a couple fairy-tales and math problems. He/It likes pretty ladies and exactly what he/it does to them is unknown.
Old Lady: The wisest and most trusted people in Russian fairy-tales. Counsel-givers and rumor-spreaders.

Ivan-Tsarevitch, tired of having his "friends" carried off by the dreaded Zmei Gorynych decided to save his town by challenging him to a duel.  Now, Zmei Gorynych had no great desire to see Ivan-Tsarevitch's legendary strength firsthand, so he proposed a duel of wits, "to add a little variety", and Ivan-Tsarevitch was very relieved that he didn't have to spoil anyone's slightly modified view of his strength.
   An old lady had once told Ivan-Tsarevitch that around Zmei Gorynych's dwelling there are many streams, nine of which are poisoned. Each of these was numbered and if you drink some water from  one of the streams, then water from a stream with a greater number works as antidote. There is a tenth stream, inside Zmei Gorynych's cave, which beats all.
   Zmei Gorynych said that they should meet near the old oak tree, bringing with them water from a stream.  Each would give this water to the other duelist. This duelist was then to go and do whatever he/it could to prolong his/its survival. Zmei Gorynych was very proud of his plan, as he knew what he would do: bring water from the tenth stream that only he could access and give Ivan-Tsarevitch some. When Ivan-Tsarevitch gave him some water, he would drink some of the tenth stream, counter-acting whatever Ivan gave him.  A fool-proof plan, right?
   The next day, Ivan-Tsarevitch and Zmei Gorynych met, drank each other's water, and then went off. In half an hour, Ivan-Tsarevitch was good as new, and Zmei Gorynych was dead, poisoned.

 How? Where did Zmei Gorynych's plan go wrong?

For the answer, which I really hope you don't look up because you're gonna feel stupid if you do, go to answersdiscarded.blogspot.com, and I'm not putting it as a link, so that you'll think about it. Answer number two. 

The Riddle of the Three Doors

     You are a noble prince, and you are on a quest to save your beloved princess. The wicked Dragon has captured her and locked her up in his dark tower.  None have yet defeated this vile creature, but nothing will stop your determination to challenge it.  However, the monster had two cups of strong, rich, coffee this morning, and is feeling benign.  It leads you up to three doors, and says:
  "Two of these doors have tigers behind them, but one leads to your princess. You can choose."
One out of three is a poor chance for such a valiant prince, but fighting the dragon you stand no chance at all,  so you sigh and step towards a door.
  "Stop.  Two cups of coffee have made me soft indeed," says the Dragon, "About the door you are about to open I will say nothing, but behind THIS door," he opens a door just a crack so that you can see the tiger within, "contains a tiger."

Now cometh the tricky part. Should you, prince, step away from the door you chose and open the other one (not the one that the Dragon opened, but the one that's left), or should you proceed and just open the one you were about to open?

THAT is the question.

Not some to be or not to be...


To find the answer, go to answersdiscarded . blogspot . com, and no, I'm not putting it as a link, so that you have SOME time to think about the riddle. (answer number 1).