document.write( "Question 1190253: Topics In Contemporary Math\r
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\n" ); document.write( "\n" ); document.write( "Use truth tables to determine if each of the following arguments are valid or invalid.\r
\n" ); document.write( "\n" ); document.write( "2) If you are superstitious, then do not walk under a ladder.
\n" ); document.write( "If you do not walk under a ladder, then you are superstitious.
\n" ); document.write( "Therefore, you are superstitious and you do not walk under a ladder.\r
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Algebra.Com's Answer #821905 by math_tutor2020(3817)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "S = you are superstitious
\n" ); document.write( "W = you walk under a ladder
\n" ); document.write( "~S = you are not superstitious
\n" ); document.write( "~W = you do not walk under a ladder\r
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\n" ); document.write( "\n" ); document.write( "Premise 1: S -> ~W
\n" ); document.write( "Premise 2: ~W -> S
\n" ); document.write( "Conclusion: S & ~W\r
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\n" ); document.write( "\n" ); document.write( "Truth table:\n" ); document.write( "\n" ); document.write( "
Premise 1Premise 2Conclusion
SW~S~WS -> ~W~W -> ~SS & ~W
TTFFFTF
TFFTTTT
FTTFTTF
FFTTTFF
Notes:
  • P -> Q is false when P is false and Q is true, otherwise it's true.
  • P & Q is true when both P and Q are true together, otherwise it's false
  • Whatever you find in column S, flip it to get ~S, and vice versa. Same goes for W to ~W as well.
In the table above, the row marked in red highlights a case when we have all true premises but they lead to a false conclusion.
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\n" ); document.write( "\n" ); document.write( "This directly leads to the fact the argument is invalid.
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