How quickly can you find out what is unusual about this paragraph? It looks so ordinary that you would think that nothing was wrong with it at all and, in fact, nothing is. But it is unusual. Why? If you study it and think about it you may find out, but I am not going to assist you in any way. You must do it without coaching. No doubt, if you work at it for long, it will dawn on you. Who knows? Go to work and try your skill. Par is about half an hour.

Sam Loyd was only 17 when his “Trick Mules Puzzle” swept the country in 1858. He finally sold it to P.T. Barnum for $10,000.

Print this page and cut out the three pieces along the dashed lines. Now arrange them so that it looks like each jockey is riding a mule. You may overlap the pieces, but you mustn’t fold them.

It’s harder than it looks.

Tom and Dick were born on the same day of the same year to same mother and father. They look almost exactly alike, yet they are not twins. How can this be?

Can you name a common English word, besides sugar, in which the initial s is pronounced sh?

A large truck had become wedged under an underpass. The driver couldn’t move it backward or forward, and traffic was beginning to back up behind it.

He was on the point of desperation when a little boy approached him and offered a suggestion. A few minutes later the truck was on its way. What did the boy tell the driver?

In the dusty street of an Old West mining town, a classics professor was stunned to find a post bearing this inscription:

TOTI
EHORS
ESTO

What was the post for?

If you start at the North Pole and walk one mile south, one mile east, and one mile north, you’ll find yourself back at your starting point.

The North Pole is not the only point with this property on Earth’s surface. In fact, there are any number of such points. Where are they?

I am greater than God, and more evil than the devil. Poor people have me. Rich people want me. And if you eat me, you’ll die. What am I?

Suppose you put a coin into an empty bottle and then insert a cork in the bottle’s opening. How could you retrieve the coin without breaking the bottle or pulling out the cork?

Another puzzle from Henry Ernest Dudeney:

“In the illustration Professor Rackbrane is seen demonstrating one of the little posers with which he is accustomed to entertain his class. He believes that by taking his pupils off the beaten tracks he is the better able to secure their attention, and to induce original and ingenious methods of thought. He has, it will be seen, just shown how four 5’s may be written with simple arithmetical signs so as to represent 100. Every juvenile reader will see at a glance that his example is quite correct. Now, what he wants you to do is this: Arrange four 7’s (neither more nor less) with arithmetical signs so that they shall represent 100. If he had said we were to use four 9’s we might at once have written 99 9/9, but the four 7’s call for rather more ingenuity. Can you discover the little trick?”