From the category archives:

Riddles

For the Love of Nonsense

12.04.2009

I love these. Used to spend days with them as a kid. Via Pentagram:
Harry Pearce was called on by Saks Fifth Avenue over the holidays to add a dash of festive cheer to their seasonal catalog. The catalog makes holiday shopping so easy that Saks decided to sprinkle its pages with 108 of Pearce’s Typographic [...]

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Riddle of the Table of Three

11.06.2009

Here’s a cool little one to roll around for the weekend.
Three and only three people, Jack, Amy, and George, are sitting at a table.
– Jack is looking at Amy.
– Amy is looking at George.
– Jack is married.
– George is unmarried.
Question: Is a married person looking at an unmarried person?
A. Yes
B. No
C. Cannot be determined

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Symmetry: Reality’s Riddle

11.02.2009

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The world turns on symmetry — from the spin of subatomic particles to the dizzying beauty of an arabesque. But there’s more to it than meets the eye. Here, Oxford mathematician Marcus du Sautoy offers a glimpse of the invisible numbers that marry all [...]

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Erin solving the U2 Riddle

10.17.2008

The U2 Riddle, one of my favorites, has been posted on this site for a few years now. It’s one of the entries that has drawn lots of traffic, and is in fact the #1 result on a Google search for “u2 riddle”.
A few weeks ago, my cousin Erin and I were driving back from [...]

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An unannounced open-book quiz

05.08.2008

Solve for x:
1. XLGEBRAX
2. xray = black + white
3. 2x or not 2x. That is the question.
4. (9 + 7x/2 = (4 – 2x (6 -2x
5. Drifxod
6. $ = mxy
Solve: (hint: “When in Rome…”)
7. n1ne
8. sk2ng
9. f4e
10. se5en
11. mo6ng
12. s9
13. e10it
Source and answers to follow.

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5+5+5=550

03.14.2008

A doozy. Using a single straight line to the left of the equals sign, make the following statement true:
5+5+5=550
Think about this one. It’s worth it. There are two correct answers. If you give up (but don’t!), you can go google it.

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Awareness test

03.13.2008

Be sure to watch it twice.

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The Riddle of the Bag of Gold

03.13.2008

You are presented with ten burlap bags full of coins. Nine of these bags contain counterfeit coins; one bag contains real gold coins. A counterfeit coin is visually identical to a real coin, and you do not know which bag contains the real gold.
Each counterfeit coin weighs exactly 1 gram, while each real gold coin [...]

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Lizzie Widdicombe of The New Yorker

02.19.2008

Lizzie Widdicombe of The New Yorker. Wrote an article about the bash. Dude, this woman is a genius. What makes me label her so? Read, count, and pay close attention.

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Been Called

12.09.2007

Been called:
An ace; a bad lad; jail cell bailed; a doodlin’ non-blonde; ice-cold and doobie-enabled; a b-load-laced lid; a candid and jaded lion; banned and canned; all bad boiled blood and bone; old, lean, and clean; bedded and laid; a doll bod, dialed and dancin’; a bed candle (LOL); nailed and loaded; an idol, blinded [...]

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The Riddle of the Goose in the Bottle

12.07.2007

Imagine you have a large glass bottle with a goose trapped inside it. How can you get the goose out of the bottle without breaking the bottle or harming the goose?

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Thinking outside the box

07.30.2007

A classic exercise in creative thinking, with a solution that offers the essence of how to think about design. Your task: Without taking pen off paper, and using only four straight lines, connect the nine dots.
I’ll post the answer in a few days.

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The Traveler’s Dilemma

06.09.2007

The Traveler’s Dilemma

When playing this simple game, people consistently reject the rational choice. In fact, by acting illogically, they end up reaping a larger reward–an outcome that demands a new kind of formal reasoning
By Kaushik Basu
Lucy and Pete, returning from a remote Pacific island, find that the airline has damaged the identical antiques that [...]

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The Riddle of the Thousand Lockers

04.10.2007

One thousand students stand in line outside a school, each numbered 1 to 1000. In the school are one thousand closed lockers, each numbered 1 to 1000. One by one, the students go into the school and “change the state” of the lockers. That is, if a locker is open, they close it; if it [...]

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Andreas teaches a class

01.04.2007

Friend, teacher, mathematician extraordinaire, and General Director of Reprise Records Andreas Wettstein demonstrates how to hit the Pause button just before discussing the gorgeous cello section on The Unforgettable Fire’s title track.
See anything familiar on the whiteboard behind him?
Incidentally, I just noticed that this site has become #1 on Google for “U2 Riddle”. No wonder [...]

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Riddle of the Burning Ropes

11.30.2006

Here’s a gorgeous logic problem I heard recently:
You’re given two ropes and a lighter. These are your only tools.
Each of the two ropes, when lit on one end, will take exactly one hour to burn all the way through to the other end. However, neither of the ropes burn at a constant rate. For instance, [...]

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