Question

Write the negation of the following.

11 < 15 and 25 > 20

Answer 1

Let p: 11 < 15,
      q: 25 > 20
Then the symbolic form of the given statement is p∧q.
Since ∼ (p ∧ q) ≡ ∼ p ∨ q, the negation of the given statement is:
11 `≥` 15 or 25 `≤` 20