ExamBro
ExamBro
MHT CET · Maths · Mathematical Reasoning

The statement \([(\mathrm{p} \rightarrow \mathrm{q}) \wedge \sim \mathrm{q}] \rightarrow \mathrm{r}\) is a tautology, when \(\mathrm{r}\) is equivalent to

  1. A \(\mathrm{p} \wedge \sim \mathrm{q}\)
  2. B \(q \vee p\)
  3. C \(\mathrm{p} \wedge \mathrm{q}\)
  4. D \(\sim q\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(\sim q\)

Step-by-step Solution

Detailed explanation

pqr\(p\) \( \rightarrow\) \(q\)\(\sim q\)\(( p \rightarrow q )\)\( \wedge \sim q\)\([( p \rightarrow q ) \wedge\)\( \sim q ] \rightarrow r\)
TTTTFFT
TTFTFFT
TFTFTFT
TFFFTFT
FTTTFFT
FTFTFFT
FFTTTTT
FFFTTTF

\(\therefore \quad[(p \rightarrow q) \wedge \sim q] \rightarrow r\) is a tautology when all the entries in the last column are \(T\), which is only possible when \(r \equiv \sim q\)