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Here's the ANSWER to Our STEM Puzzle – How Did YOU Do?
April 24, 2010


Our friends at Carnegie Mellon University’s, Women@SCS, shared this tricky puzzle about pizza and pepperoni with us. If you solved it correctly, you’ll win a t-shirt! See how you did!

Here Was the Puzzle to Solve:
You and a friend are making a pepperoni pizza. You make a game of it. Whoever places the last pepperoni wins. You take turns placing a pepperoni on the pizza. Each pepperoni is not allowed to overlap with another and must lie entirely within the pizza crust.

The game continues until there are no more spots to place pepperoni. Whoever places the last pepperoni wins!

What strategy can guarantee a win?

> Hint: What if you played the same game on a circle?

Here’s the Answer to the Puzzle:
The first player has a winning strategy: she puts a pepperoni in the center of the pizza. The other player puts a pepperoni wherever she wants. Then, the first player puts her pepperoni symmetrically (with respect to the center of the pizza) to the pepperoni that the other player has just placed. And so on, the first player just copies through symmetry the previous move of the second player. Eventually, the second player won’t find an empty spot and the first player wins.

We’ve published your answers today, April 24, 2010. Did you get the answer correct? If so, you win a fabulous t-shirt!

Thank you, CMU’s Women@SCS for this cool puzzle!

Next week we’ll have another iTwixie STEM (science, technology, engineering and math) puzzle from our friends at CMU’s Women@SCS!

{pub}Login (or join and then login) and come back to this page to send in your answers to the puzzle!{/pub}

{reg}Remember, none of your answers will show up until April 24, 2010, when we announce the solution to this puzzle! Good luck!{/reg}

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