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 < 0 when the replacement set is the set of whole numbers?

1. {0}

2. {….-3, -2, -1, }

3. {…….,-3, -2, -1, 0}

4. Null set

Which of the following statements is not true ? (r is a positive integer)

1. If p < q then p - r < q - r

2. If p ≥ q then -pr ≥ -qr

3. If p > q, then $\dfrac{p}{r} \gt \dfrac{q}{r}$

4. If p ≤ q then p + r ≤ q + r

Which of the following statements is true? (r is a positive integer)

1. If p ≥ q, then $-\dfrac{p}{r} \le -\dfrac{q}{r}$

2. If p ≤ q then pr ≥ qr

3. If p > q, then -pr > -qr

4. If p < q then p - r > q - r