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Monday, January 26, 2015

Problem of the Week

Like the start of each week, we have posted the following problem on our Facebook, Twitter, and Google + pages. We found it in the archive on mathschallenge.net and we challenge you to warm up your math muscles this cold Monday morning.

Click the picture to enlargen!

I solved the problem for this week pretty quickly. It just took a pen and paper and a little logic. Here's my solution and thought process after the jump...


Click the picture to enlargen!

So we can see that our two discs each have a 5 and an 8 on a face. The reverse of the disc with 5 is 2, and the reverse of the disc with 8 is 9. 

Did you solve this problem a different way? Have any questions about the math shown here? Let us know in the comments!
-Tori

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4 comments:

  1. UnknownJanuary 27, 2015 at 10:49 AM

    I went through the same options, but in my head. This one was extremely easy.

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    Replies
    1. Center of MathematicsJanuary 28, 2015 at 9:11 AM

      I agree, this one was easy. But we do like to have a variety! Thanks for commenting!

      Delete
  2. MicheleJanuary 27, 2015 at 4:44 PM

    Funny. I did it in my head and came up with 6 on the other side of the 5 (6 + 8 = 14) and 5 on the other side of the 8 (5 + 5 = 10 and 5 + 6 = 11).

    Am I wrong? Or are there two sets of possible answers here?

    ReplyDelete
  3. Center of MathematicsJanuary 28, 2015 at 9:12 AM

    Hi Michele, your answer would be correct if not for the qualification in the problem. It states that there are four different numbers. Thanks for your comment!

    ReplyDelete

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