Case of the Curious Rows

Nov 05, 2011

RAY: A landscaper returns from work and is sitting at the kitchen table with his kids. The kids ask, "Did you work hard today, Daddy?"

Dad says, "I did. I planted five rows of four trees each." His little third grader, wanting to show off her new found skills with the multiplication table, says, "You planted 20 trees, Daddy!"

He says, "No, I'm sorry, you little twerp. That's wrong. I planted 10 trees." She responds, "That's impossible!"

The dad responds, "No, it isn't, and here's a hint: If you look at one of the math or history test papers that your teacher has returned to you recently, you're going to find the answer."

The little girl sits there and thinks for a minute, and then she says, "I've got it!"

What did she find on her paper that gave her the answer?
RAY: The question was, how did the landscaper plant 10 trees in five rows of four each?

TOM: Yeah. How did he do it?

RAY: What the little girl finds on her paper is something that you often find on graded papers from your third-grade teacher. At the top of the page is a star. And if you draw a five-pointed star, and you put a tree at every intersection point and a tree at every vertex, you end up with 10 trees, right?

TOM: Five rows of four trees each. Pretty good!

RAY: Do we have a winner?

TOM: Yes, we do. Our winner is Catherine LaFeriere from Highland, Maryland. Congratulations Catherine!

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