A Multiplication Based Logic Puzzle

131 and Level 4

131 is a prime number. 131 = 1 x 131. Its only factors are 1 and 131. Prime factorization: none.

How do we know that 131 is a prime number? The square root of 131 is an irrational number approximately equal to 11.45. If 131 were not a prime number, then it would be divisible by at least one prime number less than or equal to 11.45. Since 131 cannot be divided evenly by 2, 3, 5, 7, or 11, we know that 131 is a prime number.

131 is never a clue in the FIND THE FACTORS puzzles.

2014-21 Level 4

Excel file of puzzles and previous week’s solutions: 10 Factors 2014-05-26

2014-21 Level 4 Logic


Comments on: "131 and Level 4" (2)

  1. Well, that one was harder, but once I got the 6’s squared away things fell into place.


  2. ivasallay said:

    There certainly were several places 6’s could have gone. Thanks for solving the puzzles week in and week out!


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