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Every month we will give you a math/statistics brain teaser that lets you test your knowledge with a fun problem.

This Month's Challenge: Lockers

Suppose you're in a hallway lined with 100 closed lockers.
You begin by opening every locker. Then you close every second locker. Then you go to every third locker and open it (if it's closed) or close it (if it's open). Let's call this action toggling a locker. Continue toggling every nth locker on pass number n. After 100 passes, where you toggle only locker #100, how many lockers are open?

Click here for answer!

Many of the ideas in these Teasers come from thoughts formed by some of the great mathematical/statistical geniuses in history. To learn more about them and to take a fun quiz to find out which famous mathematician through history most interests you, try our Mathematicians' Quiz.

Or if you'd like more Math/Science fun you might want to try...

Dare to Compare
Now with both 4th and 8th grade level questions!

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