It is given that if then , and if then not . Which of the following must be true?

Answer and explanation

Correct answer: B. If then not

  1. Step 1: Suppose is true. Then is true, and so cannot be true (because would make false). Hence .
  2. Step 2: None of the other statements can be derived from the two given implications.
Answer
If then not .
Why not the others: 'If then ' and 'if then ' reverse implications; 'both true' contradicts the facts; 'if not then ' is not forced since neither nor need be true.

Practise more Valid deductions.

Free questions with an explanation for every one, and full timed TMUA mock tests.