Dividing the Smart Kids

Feb 04, 2008

RAY: This is short and sweet, unlike last week's puzzler.

My freshman class in college was over a 1000 students; in fact it was 1058. And half of them were smart enough to advance beyond first-semester calculus. So that whole group of kids was then allowed to enroll in Calculus 2. Each of those sections of advanced calculus had the same number of students. How many sections were there?

Seems like not enough information, right? But there is.
RAY: We'll do a little math here. If I were to ask you factor the number eight, you would say one and eight, and two and four. If I asked you to factor 529, which happens to be half of 1058 (the number of students that were allowed to take advanced calculus), the factors are clearly 529 and one, and 23 and 23.

So 529 is almost a prime number, I have to call it a subprime number, and for that reason I didn't have to give out any more information. There were 23 sections, and each section had 23 people in it.

So who's our winner?

TOM: The winner is Naomi Koshel, from Cherry Hill, New Jersey, and for having her answer selected at random from among the of correct answers that we got, Naomi's going to get a 26-dollar gift certificate to the Shameless Commerce Division at Car Talk.com, with which she can get a couple of our Still Not Canceled mugs.
Congratulations Naomi!

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