RAY: This was sent in by a fellow named John Whittier. He writes, "This is the season for Cub Scouts all over the country to hold their pine wood derby races." For those of you who don't know what this is, it's a contest where kids build little wooden race cars. They give you a block of wood and four wheels if you're lucky and a bunch of nails.

TOM: And you make a car out of it.

RAY: Yeah. Anyway, he says, "My two sons built their cars and wanted to compete against each other at home prior to the real race. So I built a simple racetrack out of materials that I had on hand. I only had enough material to build a one-lane track, but not to worry, I planned to run the cars individually and use a stopwatch to time each of them. So son A would put his car at the top and let it go, I'd start the watch, and when it got across the finish line, I'd click the watch again. Well when we attempted to hold these races I discovered that the cars traversed my little track so quickly that I couldn't start and stop the watch fast enough to accurately measure the times."

TOM: Sure, that baby zoomed.

RAY: "So I couldn't really determine which car was faster, we couldn't do it. But then my younger son who was eight years old at the time came up with a solution. Now, don't forget all he had was the two cars, the test track, which we know is kind of short, the stopwatch, a quart of Filippo Berio Extra Virgin Olive Oil, a liter of Welch's Grape juice, and the three of us, the two boys and myself. What solution did my son come up with?"

Well, it doesn't involved the Filippo Berio Olive Oil. It doesn't involve the stopwatch. He very simply said, "Let's put both cars on the track, one behind the other."

TOM: Um hm.

RAY: If the front car, that is the car closest to the finish line is faster when we release the two cars simultaneously, of course, that one will pull away from the other one, and it will be the faster car.

TOM: Otherwise the other one will push it over there, over the fast one.

RAY: Well, once you've done that first heat you're going to reverse the position of the cars, and see if in fact that no gap opens and then the rear car, which had been the front car, will be the faster car.

TOM: An eight-year-old.

RAY: Eight-year-old little twerp. Good work. So who's our winner Tommy.

TOM: The winner is Don Eaton from Charleston, South Carolina.

[ Car Talk Puzzler ]