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      3 3 8 8 Puzzle

      1 March, 2001
      March 2001

      3 3 8 8 puzzle

      Using the four numbers 3, 3, 8, and 8, and the usual four arithmetic operations (addition, subtraction, multiplication and division), can you make the number 24?

      This looks a bit too easy (3 × 8 = 24), until I tell you that you have to use all four numbers - both 3s and both 8s. No silly tricks allowed - you can't use an 8 and a 3 to make 83, or raise numbers to powers or take square roots or factorials or anything else of that kind.

      You can use fractions on the way, of course, but the final answer must be exactly 24. For example: 3 × 8 + (3/8) makes 24 and three-eighths, which is quite close, but no banana.


      You can send your solution by e-mail to <plus@maths.cam.ac.uk>.

      For some challenging mathematical puzzles, see the NRICH puzzles from this month or last month.

      We have received a couple of correct solutions to the PLUS issue 13 puzzle. If you don't want to keep trying it yourself, you can see how it's done.

      Solution link
      3 3 8 8 - Solution
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      Anonymous

      27 July 2010

      Permalink
      Comment

      wrong,

      there is a way and here it is

      3 cubed = 27

      27 - 3 =24
      then with the two 8s you can add and take away or times and divide.

      bye

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      Anonymous

      30 November 2016

      In reply to answer by Anonymous

      Permalink
      Comment

      3 cubed equals 3 times 3 times 3 and you only have 2 threes

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      Anonymous

      15 March 2011

      Permalink
      Comment

      How to make 21 with 1, 5, 6 and 7?

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      Anonymous

      2 March 2014

      In reply to Another one not that easy by Anonymous

      Permalink
      Comment

      6 / (1 - 5 / 7)
      = 6 / (2 / 7)
      = 6 * (7 / 2)
      = 21

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      Anonymous

      18 March 2011

      Permalink
      Comment

      8/(3-(8/3))
      8/((9-8)/3)
      8/(1/3)
      24

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      Anonymous

      14 January 2012

      Permalink
      Comment

      Divide the first 3 by itself (Not another digit) that equals 1 plus the next digit 3 = 4 times 8 = 32 minus 8 = 24.

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      Anonymous

      16 August 2012

      In reply to 3388 puzzle by Anonymous

      Permalink
      Comment

      This is wrong because you have already used 3 three times. Duh!

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      Hina

      1 July 2023

      Permalink
      Comment

      (3/3)x(8/8)

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