A Multiplication Based Logic Puzzle

175 and Level 2

 

175 is a composite number.
Factor pairs: 175 = 1 x 175, 5 x 35, or 7 x 25
Factors of 175, 1, 5, 7, 25, 35, 175
Prime factorization: 175 = 5 x 5 x 7 which can be written 175 = (5^2) x 7

When the double-the-last-digit-and-subtract-it-from-the-remaining-numbers divisibility trick for 7 is applied to 175 we get: 17 – (5 x 2) = 17 – 10 = 7, a multiple of 7, so 175 can be evenly divided by 7.

2014-28 Level 2

Excel file of puzzles and previous week’s factor solutions: 12 Factors 2014-07-14

2014-28 Level 2 Factors

 

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