JEE Main 201911 JanuaryMorning Shift
- Exam
- JEE Main
- Year
- 2019
- Date
- 11 January
- Shift
- Morning Shift
- Subject
- Mathematics
- Chapter
- Mathematical Reasoning
JEE Main 2019 · 11 January · Morning Shift · Mathematics · Mathematical Reasoning
If q is false and p q rightarrow r is true, then which one of the...
If is false and is true, then which one of the following statements is a tautology?
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
q[(p \wedge q) \leftrightarrow r](p \wedge q)[ is true
Hence is false
Option (1): says ,
Since is false
Hence can either be true or false
Option (2): says is false
Since, is true and
is also true
Hence, it is a tautology
Option (3):
i.e.
It can either be true or false
Option (4):
Since, is false
Hence, is false.