From the Department of Very Curious Math

Dec 01, 2003

RAY: This puzzler was sent in by Tony Bys. He writes:

"After the long, miserable spring we had here in the great Northeast, we finally had a nice sunny, warm day. It happened to coincide with my 12-year-old son being home from school on summer vacation. I asked him if he wanted to go for a ride, and he said, "Not really, Dad."

Then I said those magic words: "ice cream." He quickly changed his mind.

As were riding over to the nearby creamery, he turned to me, and said, "I know that one and six is six. But, is two and five 10?"

"No," I replied, "two and five is twelve."

"Then what's 3 and 3?", he asked.

"Seventeen," I responded.

"Oh yeah," he said. "I think I've got it now."

The question is, what the heck were Tony and his son talking about?

TOM: Let me see if I've got this right. They're in the car. They're driving to the creamery. Is that right?

RAY: I didn't precisely say that. And that's a hint.


RAY: Here's the answer. They were riding on their 21-speed bicycles. A 21-speed bike has three sprockets in the front and seven in the back. Seven times three is 21, right? So, one and six is when you mesh the first gear with the sixth gear, that's sixth gear, and then two and five is not ten but in fact it's 12th gear, and three and three is seventeenth gear.

So who's our winner?

TOM: The winner is Sam Wheeler from Jericho, Vermont.

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