Which of the following is not true?

1. p > q ⇔ q > p

2. p < q ⇔ q > p

3. p ≥ q ⇔ q ≤ p

4. p ≤ q ⇔ q ≥ p

Which of the following is the solution set of x ≤ 7 when the replacement set is the set of natural numbers?

1. {1, 2, 3, 4, 5, 6, 7}

2. {0, 1, 2, 3, 4, 5, 6, 7}

3. {1, 2, 3, 4, 5, 6}

4. {0, 1, 2, 3, 4, 5, 6}

Which of the following is the solution set of x ≤ 3 when the replacement set is the set of integers?

1. {0, 1, 2, 3}

2. {……,-2,-1, 0, 1, 2}

3. {………..,-2,-1, 0, 1, 2, 3}

4. {…..,-2,-1, 1, 2, 3 }