KCET2010MathematicsMathematical Reasoning
Which of the following is not true?
Options
- A( p q ) ( p q ) is a tautology
- B( p q ) ( q r ) ( p r ) is a tautology
- Cp ( q r ) ( p q ) ( p r )
- D( p q ) ( p q ) ( p q )
Correct answer
A. ( p q ) ( p q ) is a tautology
Step-by-step solution
(a) ( p q ) ( p q ) x y is a contradiction from table. (b) ( p q ) ( q r ) ( p r ) y z w A W is a tautology from table. (c) p ( q r ) ( p q ) ( p r ) p G y w ( p G ) C , represent logical equivalence from table. (d) (p q) (p q) ( p q) F x E F D , represent logical equivalence from table.