On-Air Challenge: Every answer is the name of a world capital. You'll be given a four-letter word. The first two letters are the first two letters of the city's name, and the last two are the last two letters of the country's name. For example, if you were given "loin," the answer would be London, Great Britain.
Last Week's Challenge from the Grabarchuk family: Take 15 coins. Arrange them in an equilateral triangle with one coin at the top, two coins touching below, three coins below that, then four, then five. Remove the three coins at the corners so you're left with 12 coins. Using the centers of the 12 coins as points, how many equilateral triangles can you find by joining points with lines?
Answer: 25 equilateral triangles
Winner: Chris Anderson from Portland, Ore.
Next Week's Challenge from listener Henry Hook of Brooklyn, N.Y.: What number comes next in the following series: 2, 4, 6, 9, 11, 15, 20, 40, 51, 55, 60 and 90?
If you know the answer to next week's challenge, submit it here. Listeners who submit correct answers win a chance to play the on-air puzzle. Important: Include a phone number where we can reach you Thursday at 3 p.m. Eastern.
AUDIE CORNISH, HOST:
This is WEEKEND EDITION from NPR News. I'm Audie Cornish. And time now for the puzzle.
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CORNISH: Let's start with last week's challenge from Will Shortz, the puzzle editor of the New York Times, and WEEKEND EDITION's puzzle master.
WILL SHORTZ, BYLINE: Take 15 coins, arrange them in an equilateral triangle with one coin at the top, two coins, then three coins below that, then four, then five. Remove the three coins at the corner, so you're left with 12 coins. Using the centers of the 12 coins as points, how many equilateral triangles can you find by joining points with lines?
CORNISH: Well, this was a tough one, and just about 120 of you sent in the correct answer. Our randomly selected winner this week is Chris Anderson from Portland, Oregon. Congratulations, Chris.
CHRIS ANDERSON: I thank you, Audie.
CORNISH: So, tell us, how many equilateral triangles did you find?
ANDERSON: I found 25.
CORNISH: And please tell me you used a pencil and paper to do this. You did not figure it out in your head. Make us all feel better.
ANDERSON: I actually used the church bulletin, writing during the pastor's sermon. I hope he's not listening.
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CORNISH: Sounds like you got some divine inspiration there.
ANDERSON: Perhaps, yeah.
CORNISH: And what do you do in Portland, Oregon?
ANDERSON: I work as a family physician.
CORNISH: And it's safe to say, I hope, that you're a big puzzle fan.
ANDERSON: Yes, I am. In fact, there are several of us who gather daily in our cafeteria to work out Will's dastardly puzzles.
CORNISH: Oh, cool. Well, before we continue, let me introduce you to Will Shortz then. Good morning, Will.
SHORTZ: Hi, Audie, and congratulations, Chris. And I like that adjective - dastardly.
ANDERSON: Thank you.
CORNISH: Will, welcome back to the States. I know you're back from Hungary, where you just had the World Puzzle Championships. Who won?
SHORTZ: It was a double event this year. It was a World Sudoku Championship, a day of rest, and then the World Puzzle Championship. And the results of the latter aren't known yet, but the winner of the Sudoku championship was Thomas Snyder.
CORNISH: An American? Ah, well done.
SHORTZ: And there were 31 countries with competitors. So it was a tough competition.
CORNISH: Chris, hopefully, Will will not give you anything nearly as tough. But I hope you do have your pencil and pen ready. Are you ready...
ANDERSON: I do.
CORNISH: ...to play?
ANDERSON: Yes, I am.
CORNISH: All right, Will. Take it away.
SHORTZ: All right, Chris. Every answer today is the name of a world capital. I'm going to give you a four-letter word. The first two letters are the first two letters of the city's name. The last two letters are the last two letters of its country's name. For example, if I said loin - L-O-I-N - you would say London, Great Britain; with the L-O starting London, and the I-N ending Great Britain.
ANDERSON: Sounds fun.
SHORTZ: All right. And I'll give you a hint: These first answers are all from Europe. Here's number one: main, M-A-I-N. And this is a city in an E.U. country that's in the western part of Europe.
ANDERSON: Oh, Madrid, Spain, of course.
SHORTZ: Madrid, Spain is it. Number two is pace, P-A-C-E.
ANDERSON: Paris, France.
SHORTZ: Oh, excellent. How about sten, S-T-E-N - and that's the name of an old British gun, by the way - S-T-E-N. It's a country in northern Europe.
ANDERSON: Stockholm, Sweden.
SHORTZ: That's right. How about rend, R-E-N-D? Now, this is a tough one, although it's a well-known country. It's a country surrounded by water.
ANDERSON: Oh, Reykjavik, Iceland.
SHORTZ: Reykjavik, Iceland, excellent. All right. Now, we move outside Europe. How about sale, S-A-L-E? And you're looking for a country in South America. Long, thin country.
ANDERSON: Oh, Chile and Santiago, right.
SHORTZ: Santiago is right. Good. And here's your last one: khan, K-H-A-N. It's a country in Africa.
CORNISH: Are we finally stumping Chris? Not that I want that to happen.
SHORTZ: I'll give you a hint: It's a country that borders Egypt - and specifically, to the south of Egypt.
ANDERSON: Drawing a blank.
CORNISH: It's on the tip of your tongue. I can sense it.
ANDERSON: I wish.
SHORTZ: All right. Well, I'll tell you the country...yeah, yeah, good one, Audie. Go ahead.
CORNISH: Khartoum and Sudan.
SHORTZ: Khartoum, Sudan. Nice work. OK. It took two heads on that last one.
CORNISH: Chris, great job. That was awesome.
ANDERSON: Oh, thank you, Audie.
CORNISH: 'Cause I just have my pen and pad here and it's just like, all scribbled with. Two letters here and two letters there, and none of them are adding up to capitals. I'm envious of you. Chris, for playing our puzzle today, you'll get a WEEKEND EDITION lapel pin as well as puzzle books and games. You can read all about it at NPR.org/puzzle.
And Chris, which member station do you listen to?
ANDERSON: KOPB - we're members - in Portland, Oregon.
CORNISH: Thank you so much, Dr. Chris Anderson. Thanks for playing the puzzle this week.
ANDERSON: Thanks, Audie. Thanks, Will.
CORNISH: So Will, what's our challenge for next week?
SHORTZ: Yes, it comes from listener Henry Hook of Brooklyn. And it's not too hard, I think. [POST-BROADCAST CORRECTION: Some numbers were left out of the number series for next week's challenge. The correct sequence should be 2, 4, 6, 9, 11, 15, 20, 40, 51, 55, 60 and 90.] Write down these numbers: 2, 4, 6, 9, 11, 15, 20, 40, 60, 90. What number comes next in this series?
So again, the numbers are: 2, 4, 6, 9, 11, 15, 20, 40, 60, 90. What number comes next in the series?
CORNISH: When you have the answer, go to our website, NPR.org/puzzle. Click on the Submit Your Answer link - just one entry per person, please. And our deadline for entries is Thursday, November 17th at 3 P.M. Eastern Time. Please include a phone number where we can reach you at about that time. And if you're the winner we'll give you a call, and you'll get to play on the air with the puzzle editor of The New York Times and WEEKEND EDITION's puzzle-master, Will Shortz.
Will, thanks so much.
SHORTZ: Thanks, Audie. Transcript provided by NPR, Copyright NPR.