A Multiplication Based Logic Puzzle

103 and Level 2

103 is a prime number. 103 = 1 x 103. Its only factors are 1 and 103. Prime factorization: none.

How do we know that 103 is a prime number? The square root of 103 is an irrational number approximately equal to 10.15. If 103 were not a prime number, then it would be divisible by at least one prime number less than or equal to 10.15. Since 103 cannot be divided evenly by 2, 3, 5, or 7, we know that 103 is a prime number.

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

2014-17 Level 2

This week’s puzzles and last week’s factors: 10 Factors 2014-04-28

2014-17 Level 2 factors

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Comments on: "103 and Level 2" (2)

  1. I like your explanation of how to quickly show that 103 is a prime number. I didn’t know that.

    Like

  2. ivasallay said:

    Thank you. It is a powerful time saver.

    Like

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