This proposition is true, but 40% of people get it wrong.

ysmemoirs “Every positive integer less than 1 is greater than 10000.”

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This survey was so interesting that I did a little twisted survey myself.

nishio: for any positive integer x, “if x is less than 1, then x is greater than 1”…

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  • I was so taken aback by the number of “it doesn’t follow…” that I asked an additional question.
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  • One more question
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explanation

  • The top of all surveys is correct.
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    • 1: If P is false, then “if P then Q” is true regardless of the truth of Q
    • 2: P = “x is less than 1” is false for any positive integer x
    • 3: Thus “Q if P” is true for any positive integer x.
      • If Q = “x is greater than 1”, it would be a questionnaire question text.
  • Since the majority of the correct answers are “If 3 is even, then 4 is odd” at the end, many people understand 1: “If P is false, then Q is true regardless of the truth of Q”.
  • It seems some people have judged “If x is less than 1, then x is greater than 1” to be “mathematically incorrect” or “a contradictory statement” based solely on this point.
    • This is a mistake.
    • For example, whether “1/(1/x)=x” is correct or not cannot be determined until x is specified as the source of any set.
      • If it is a positive real number, it is correct because it does not contain zero, and if it is a whole real number, it is incorrect because it contains zero.
    • Similarly, we can’t just look here to determine if “if x is less than 1, then x is greater than 1” is correct
      • Those who made the decision prematurely must have implicitly assumed that x was a real number, etc., and made the decision.

Interesting Miscellaneous

  • In France, zero is a number that is both positive and negative.”

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