RAY: Well here's the answer. You light three ends at the same time, or as close to the same time as you possibly can. So you light two ends of one fuse and one end of the other fuse.
When the first fuse, the one whose both ends are lit, has completely burned up, that's half an hour. Because if it took an hour for it to burn from A to B, one end to the other end, if you light both ends the whole fuse will be consumed in half an hour.
RAY: OK. In the meantime that other fuse has been burning. If, as soon as the first fuse has burned up completely, you light the last end. So you've used up half an hour, and now it takes another 15 minutes for the new end to catch up to the original lit end and voila!
TOM: Boy, that is very good.
RAY: Do we have a winner?
TOM: The winner this week is Becky Salon from Lunenburg, Vermont. And for having her answer selected at random from the pile of correct answers that we got, Becky is going to get a 26-dollar gift certificate to the Shameless Commerce Division at cartalk.com, with which Becky can get one of our sleek looking (not really) black, red, gray and white baseball jerseys.
RAY: Congratulations, Becky!
[ Car Talk Puzzler ]