String Puzzler, Number B

The Puzzler

RAY: Ha! We're back! You're listening to Car Talk with us, Click and Clack, the Tappet Brothers, and we're here to discuss cars, car repair and, uh, the new Puzzler. Now, as promised, this is the second in a series of two...

TOM: Yeah. Of the string Puzzlers.

RAY: Of string Puzzlers. You may remember...

TOM: You might refer to it as "string theory," almost.

RAY: You could.

TOM: You could.

RAY: Yeah. You could.

TOM: And will the story here be spellbinding, as you promised?

RAY: Riveting.

TOM: Riveting?

RAY: Like blue jeans.

TOM: Riveting.

RAY: Not really. You may remember the other Puzzler in the spring regarding string.

TOM: Two pieces of string, you burn something.

RAY: There you go.

TOM: Time goes by, half an hour.

RAY: You have two pieces of string, and each of them will, if you light one end, will burn up in an hour's period of time.

TOM: Right.


TOM: But at an unpredictable rate.

RAY: At an unpredictable, nonlinear rate, so you can't say, "OK, look, I'm going to cut the thing in half and light one piece of it, and that's going to burn up in half an hour." All you know is that from beginning to end, the burn time is an hour.

TOM: Gotcha.

RAY: OK? And the old Puzzler was: How could you measure a 15-minute period of time? And you did so by lighting three ends at once.

TOM: Three?

RAY: Yes.

TOM: It's only got two ends. It's one piece of string.

RAY: No, you have two pieces of string.

TOM: Two pieces of string. Got it.

RAY: The first piece burns up in half an hour, OK?

TOM: Because it's lighting from both ends.

RAY: Both ends, OK. The second piece burns for, obviously, half an hour, because it's, what? Lit at the same time as the other two ends. And then what you do is, you light the fourth end as soon as the first two flame-fronts have met.

TOM: Boom. And that's 15 minutes.

RAY: And there you go, OK?

TOM: That's good.

RAY: That's good, yeah. And a lot of people got the answer to that.

TOM: Sure.


TOM: And I like it too.

RAY: So, now you're armed with the same two pieces of string.

TOM: Yeah.

RAY: Your Zippo lighter.

TOM: Yeah.


TOM: Yeah.

RAY: And that's it. And the question is: How do you measure six minutes?

TOM: Six minutes?

RAY: Yeah. In other words, I want you to tell me...

TOM: You might be cooking an egg, and that would be important.

RAY: How could you tell me, OK, boom! Right now, six minutes has elapsed from the...right? OK?

Think you know? Drop Ray a note!

[ Car Talk Puzzler ]

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