Hopping List

http://books.google.com/books?id=5m4ZAAAAYAAJ&printsec=frontcover&rview=1#PPA99,M1

This literary knight’s tour appeared originally in the Sussex Chess Magazine.

Start on d4, “Our”, and jump from square to square in the manner of a chess knight to assemble an eight-line verse. Like a chess knight’s tour, the correct solution visits every square on the board.

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The Stars Align

Newspapers in 1944 noted a striking coincidence:

world war ii coincidence

How can this be explained?

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Asking Directions

From Henry Dudeney:

Imagine a man going to the North Pole. The points of the compass are, as everyone knows:

dudeney - asking directions

He reaches the Pole and, having passed over it, must turn about to look North. East is now on his left-hand side, West on his right-hand side, and the points of the compass therefore

dudeney - asking directions

… which is absurd. What is the explanation?

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Mate in Zero

We’ve seen chess problems in which White must mate in half a move and even in -1 moves.

In this one White must mate in 0 — he must deliver checkmate without touching any of his pieces:

http://books.google.com/books?id=5m4ZAAAAYAAJ&printsec=frontcover&rview=1#PPA101,M1

How can he do this? Imagine that the position arose in an actual game.

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Tempting

The Earl of Yarborough offers you a wager. He’ll shuffle an ordinary deck and deal you 13 cards. If none of your cards ranks above 9, he’ll give you a thousand pounds. Otherwise you must give him one pound.

Should you accept?

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Hey Presto!

A bit of conjuring adapted from Augustus de Morgan:

1. Think of a one-digit number and remember it. (Example: 4.)

2. Write down a number of any length. Jumble the figures into another number, and subtract one from the other:

de morgan

3. Count the letters in your father’s first name, your state capital, and the name of your favorite Beatle, and add them together.

4. Multiply this number by 4 and its reverse by 5. Add these together, plus the number from step 1.

For example, suppose your father’s name is William, your state capital is Oklahoma City, and you choose Paul. That’s 23 letters in all, and 23 reversed is 32. (4 × 23) + (5 × 32) + 4 = 256.

5. Mix these figures (256) into the result from step 2 (4600708659), in any order, say 4560207086569.

Seeing nothing but this final list of figures, the conjurer names the one-digit number from step 1.

How does he do it?

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The Rejected Gun

From Henry Dudeney:

Here is a little military puzzle that may not give you a moment’s difficulty. It is such a simple question that a child can understand it and no knowledge of artillery is required. Yet some of my readers may find themselves perplexed for quite five minutes.

An inventor offered a new large gun to the committee appointed by our government for the consideration of such things. He declared that when once loaded it would fire 60 shots at the rate of a shot a minute. The War Office put it to the test and found that it fired 60 shots an hour, but declined it “as it did not fulfill the promised condition.”

“Absurd,” said the inventor, “for you have shown that it clearly does all that we undertook it should do.”

“Nothing of the sort,” said the experts. “It has failed.”

Can you explain this extraordinary mystery? Was the inventor, or were the experts, right?

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What Is It?

Here’s one of the most beautiful riddles in the English language. It’s commonly attributed to Byron, but it was composed in 1814 by Catherine Maria Fanshawe, the daughter of a Surrey squire:

‘Twas whispered in heaven, ’twas muttered in hell,
And echo caught faintly the sound as it fell;
On the confines of earth ’twas permitted to rest,
And the depths of the ocean its presence confessed.
‘Twill be found in the sphere when ’tis riven asunder;
‘Tis seen in the lightning, and heard in the thunder.
‘Twas allotted to man from his earliest breath;
It assists at his birth, and attends him in death;
It presides o’er his happiness, honour, and health;
Is the prop of his house, and the end of his wealth.
In the heap of the miser ’tis hoarded with care,
But is sure to be lost in his prodigal heir.
It begins every hope, every wish it must bound,
It prays with the hermit, with monarchs is crowned.
Without it the soldier and seaman may roam,
But woe to the wretch who expels it from home.
In the whispers of conscience ’tis sure to be found;
Nor e’en in the whirlwind of passion is drowned.
‘Twill soften the heart, and though deaf to the ear,
‘Twill make it acutely and constantly hear.
But, in short, let it rest like a beautiful flower;
Oh, breathe on it softly, it dies in an hour.

What is it?

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Thrilling Peril!

http://commons.wikimedia.org/wiki/File:Mars_Twin_Peaks_(1024px).jpg

Amy, Bob, Cindy, and Dave are the last four colonists on Mars, which is being overrun by Hideous Sand Beetles. The last evacuation ship leaves in 16 minutes. To reach it, they must pass through the Soul-Freezing Tunnel of Yx, which can accommodate only two people at a time. And anyone passing through the tunnel must light his way with the Fabulous Oracle of Zeb. (Mars is very dramatic.)

  • Amy can travel the tunnel in 1 minute.
  • Bob can travel the tunnel in 2 minutes.
  • Cindy can travel the tunnel in 5 minutes.
  • Dave can travel the tunnel in 8 minutes.

This is a problem. If Amy and Dave go first, they’ll reach the other side in 8 minutes (Dave’s top speed). If Amy then runs back and escorts Cindy, and then Bob, she and Bob will be only halfway through the tunnel when the ship departs. Are they doomed?

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