Friday, February 29, 2008

A Puzzle for Leap Day, 2008 -- Can you make 97?

Today is February 29, a special date that only appears on our calendars every four years. There are exceptions to this 4 year rule on century years (those ending in 00). These years are NOT leap years unless the century is evenly divisible by 400. For example, 2000 was a leap year, but 2100 will NOT be. The cycle of leap years on our calendar repeats in a 400 year cycle. Within that cycle there will be 97 leap years.

All this historical information was a way to introduce this week's math puzzle.

Q: Using each of the digits in 2008 and standard math operations, can you write an expression that equals 97?
  • Each of the digits 2, 0, 0, 8 must be used. (2 and 8 will appear once, 0 will appear twice.)
  • You may use standard math operations of +, -, x, /, √(square root), ^(raise to a power) and !(factorial) along with parentheses for grouping.
  • Decimal points and multi-digit numbers may be used (e.g. 20, 208, .02 or 2.8
  • If squaring is done, that uses up the digit 2.
  • 0! is agreed to have a value of 1.
  • Anything raised to the zero power (i.e. x^0) is 1, but 0^0 may not be used (undefined)
  • The integer/floor/ceiling/round functions may NOT be used.
  • Change of bases may NOT be used.
  • Logarithms may NOT be used.
  • Sine and Cosine may NOT be used.
Edit: The answer is now available in the comments... but don't look if you still want to figure it out on your own.

Thursday, February 28, 2008

NPR Sunday Puzzle (Feb 24): Uh-oh! Oops! Drat! Where is that darn city?

NPR Sunday Puzzle (Feb 24): Uh-oh! Oops! Drat! Where is that darn city?:
Q: Take the name Seattle. The letters in the odd positions are S-A-T-E, which spell SATE. Think of another U.S. city name, in seven letters, in which the letters in the odd position spell a common four-letter exclamation. What's the city and what's the exclamation?
My wife had the answer right away but I was off thinking world cities, European capitals, etc. Once I got back to U.S. cities it came to me right away. Isn't L. L. Bean associated with this city? No? Oh well, maybe I'm wrong. Post your clues but don't reveal any answers until after the deadline (Thursday 3pm ET). Talk to you later!

Edit: We'll have to see what the official answer is from NPR. It might be Oshkosh, but I was thinking Chicago, home of the elevated transit system called the "L" and a new sculpture in Millennium Park entitled "Cloudgate", but known more familiarly as "The Bean".

Friday, February 22, 2008

Use the digits 1 through 9 exactly once...

This is a quick puzzle that shouldn't be too difficult to figure out.

Q: Arrange the digits 1 through 9 to form three 3-digit perfect squares. You must use each of the nine digits exactly once.

Feel free to add a comment with your answer, along with how you solved it.

NPR Sunday Puzzle (Feb 17): Surprise, surprise, another word problem!

NPR Sunday Puzzle (Feb 17): Surprise, surprise, another word problem!:
Q: There's a seven-letter word for something that is a measure of wealth and power. The first four letters name an animal that is a symbol of power. And the last four letters name another animal that is a symbol of power. What's the word?
These simple word puzzles are getting old. There are so many clues in what Will provided again this week, that I'm 99.5% sure that most people will solve this almost immediately. If you say you spent more than an hour figuring this out, I'd call you on it and say you are lying.

Edit: This week's clues, "getting old", 99.5% (as in purity) --> Gold Bullion. Hopefully I don't have to explain the "bull" part of calling you on it. And lying sounds a lot like "lion".

Friday, February 15, 2008

This Number is a Two-Timer...

Here's a math puzzle for you to ponder. Feel free to post your answer in the comments.
Q: A positive integer has a unknown number of digits but it ends in a two. If the two is moved to the front of the number the new number will be exactly double the old. What is the number?

NPR Sunday Puzzle (Feb 10): Put on a Bikini

NPR Sunday Puzzle (Feb 10): Put on a Bikini:
Q: Name a city in six letters that's a popular tourist destination. Divide this name in half, move the first three letters to the end keeping everything else in order, you'll name some places where people like to relax. What are they?
When I think of tourist destinations, my first thought is they must include the sun as a primary reason for going. Think hot, hot, hot!

Edit: Hidden in my hint: "...include the sun as a primary...". The item in italics is an anagram of both answers. And the mention of heat applies to both as well.
A: NASSAU (capital of the Bahamas)--> SAUNAS

Friday, February 08, 2008

Create a foldable 3-D dodecahedron calendar

I discovered a fascinating site a few years back and completely forgot about it. You've probably seen a 3-D calendar with each month on one of the faces of a dodecahedron. But have you ever wanted to print and construct your own? Ole Arntzen of Norway created a webpage that lets you pick a year, a language and a few other options and then it creates a printable template for a 12-sided calendar.

You can generate a ready-to-print PDF file, or an editable PostScript file. With a little editing of the PS file, you can add holidays, birthdays, school breaks, anniversaries, etc. Take a look!

Thursday, February 07, 2008

NPR Sunday Puzzle (Feb 3): A Sporting Chance

NPR Sunday Puzzle (Feb 3): A Sporting Chance:
Q: Name a sport that has only one vowel in it. Change the vowel to a different vowel. If you read the result backward, you'll get a piece of equipment used in that sport. What's the sport and the piece of equipment?
I've gone over looking for the answer to this week's puzzle. Of course it makes sense that the answers are both one syllable, but after trying for several hours now, my interest in solving the puzzle this week is waning.
Edit: Time to reveal my clues:
"gone over looking for", "Of course..." --> GOLF
"waning" = "flagging" --> FLAG