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Unformatted text preview: P ractice for Quiz #5 1. Given that A and B are t rue propositions while X and Y are false propositions, the t ruthvalue of ‘~(A & ~X) v ~(~X ⊃ Y)’ is a. T r ue b. False 2. When p is t rue, q is false, and r is t rue, the t ruth-value of ‘~((p ⊃ r ) ⊃ (q & ~r))’ is a. T r ue b. False 3. Given that Obama is the president, Sarah Palin is not t he vice-president, and Biden is t he vice-president, the t ru th-value of the proposition ‘If Sarah Palin is not the vicepresident, then either Obama is the president or Biden is not the vice-president’ is p=Obama is president q=Palin is not the vice b=Biden is the vice president q ⊃ (p v ~b) T ⊃ ( T v F) TvT T a. T r ue b. False 4.The argument form ‘If p, then q; ~q; therefore, ~p’ is a. Valid b. Invalid 5. The argument, “If i t is a fratechette, then i t is gravitational. I t is not a fratchette. T herefore, it is not gravitational,” is p⊃q ~p ∴ ~q p q p⊃ q ~p ~q T T T F F T F F F T F T T T F I NVALID F F T T TOK a. Valid b. I nvalid 6. T rue or false: An argument form is valid if and only if it is impossible for any argument having that form to have t rue premises and a false conclusion. a. T r ue b. False ...
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- Fall '08
- Vice President of the United States, Sarah Palin, vice-president, Argument form, false propositions, rue propositions