Join the Car Talk Community!

Mathematic Mistake

The Puzzler


RAY: 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 the new puzzler.

TOM: I noticed you didn't make any promises about the puzzler like it's scintillating, exciting, automotive, folkloric, brilliant!

RAY: I didn't really know which puzzler I was going to use.

TOM: OK.

RAY: Did I do the one with the poison wine glass?

TOM: Not!

RAY: Not recently. Here it is.

TOM: Oh, you have one!

RAY: Well, yes I do. Of course I have a puzzler!

TOM: All right.

RAY: Everyone, almost everyone remembers from his or her days in school the Pythagorean Theorem.

TOM: Yes.

RAY: A squared, plus B squared, equals C squared. And there are numbers like three, four and five; five, 12, 13 which satisfy that little equation.

TOM: Yeah.

RAY: And many hundreds of years ago a French mathematician by the name of Fermat said, this only works for squares. He said, if you take A, B, and C, integers A, B, and C...

TOM: Yes.

RAY: And there are some A squared plus B squared that will equal C squared, and we believe that. We know we have verification of it.

TOM: Yeah, we got real numbers that fit it.

RAY: We got real numbers that work.

TOM: Right.

RAY: He said, if it isn't squared but it's something else like cubes or to the fourth power or to the fifth power --

TOM: Forget it!

RAY: It doesn't work. So, for example, there is no A cubed plus B cubed, which equals C cubed.

TOM: That's what he said!

RAY: There is no A to the fourth plus B to the fourth that equals C to the fourth. As luck would have it, a young mathematician issues a statement that he has three numbers which prove Fermat's theorem is incorrect. He calls a press conference. Now, he doesn't want to divulge everything right away. He wants to dramatize, build a little bit, does he not?

TOM: Gonna give them one number.

RAY: He gives them all three numbers. He doesn't tell the power.

TOM: Ah!

RAY: He's going to give them A, B, and C. Here are the numbers, you ready?

TOM: Oh, I got to write this down.

RAY: A equals 91.

TOM: Yeah.

RAY: B equals 56.

TOM: I know the answer already.

RAY: Wait a minute!

TOM: Yeah, I'm gonna tell you what C equals.

RAY: I'm gonna tell you!

TOM: I'm gonna tell you what it is!

RAY: Go ahead.

TOM: A 147.

RAY: Wrong. C equals 121. So, it just so happens that at this little impromptu press conference, there are all these science reporters from all the po-dunky little newspapers that are around this town. And one of the guys, one of the reporters has his 10-year-old kid with him, because this happens to be a holiday. He's off from school. And the kid very sheepishly stands up and raises his hand, and he said, I hate to disagree with you, sir, but you're wrong. The question is, how did he know?

TOM: That the guy couldn't possibly --

RAY: That he couldn't dispute Fermat with these numbers.

TOM: With these three numbers.

Think you know? Drop Ray a note!

[ Car Talk Puzzler ]

Support for Car Talk is provided by:

Donate Your Car,
Support Your NPR Station

...and get a tax break!

Get Started

Find a Mechanic


Go



Submit