A California Coastal Cruise

The Puzzler

RAY: So remember the obfuscating details? We took the same route there as we did getting back, a total of 337 miles each way. But here's the question, what is the probability that there was a place along our route that we reached at the exact same time of day on our trip to Monterey and our return trip from Monterey? What's the probability?

TOM: Wow, that's great. That sounded so complicated.

RAY: Well, it did except not really.

TOM: Luckily there's no calculations that we can do.

RAY: No. You got to just shoot for it. Here's the answer, here's the way to look at it. You're going to superimpose the two trips. Assume that you have twins that are leaving Monterey on the same day that you are leaving L.A.

TOM: Got it.

RAY: OK, they're leaving two hours later. And where you cross paths is that place. You have to pass each other, the only way you might not pass each other is this. If you left L.A. at 7:10 and you got to Monterey at 9:19 a.m. OK. So you did it in what, an hour and nine minutes.

TOM: Right.

RAY: OK. Then you wouldn't meet along the way, but that would require that you exceeded the speed limit, in fact I'm pretty sure in order to do that you'd have to travel like 160 miles an hour.

TOM: Right. Otherwise you're going to pass each other.

RAY: But I stated in the original puzzle that we pretty much obeyed the speed limit, and if you obey the speed limit there is no way that you can't pass, so the answer is the probability that you do this --

TOM: A hundred-percent!

RAY: Exactly. So who's our winner?

TOM: The winner this week is Maggie Zeeman from Atlanta, Georgia, and for having her answer selected at random from the pile of correct answers that we got, Maggie gets a 26-dollar gift certificate to the Shameless Commerce Division at cartalk.com, with which she can get our brand-new four-CD set, Field Guide to the North American Whacko.

RAY: Congratulations, Maggie, on your enormous win today!

[ 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

Promo tile

Rocket Fuel