{x : x ∈ Z and x² - 4x = 0} is equal to :

1. {4}

2. {0, 4}

3. {0, 2}

4. {2, 4}

{x : x ∈ Z and x² = 9} is equal to :

1. {3}

2. {0, 3}

3. {0, -3}

4. {-3, 3}

Set {x : x = n² - 1, x ∈ Z (integers) and 2 < n ≤ 5} is equal to :

1. {8, 15, 24}

2. {3, 8, 15}

3. {3, 8, 15, 24}

4. none of these

Set-builder form of set A = $\Big{\dfrac{1}{2}, \dfrac{2}{3}, \dfrac{3}{4}\Big}$ is :

1. ${\Big{x = \dfrac{n}{n + 1}, n ∈ N \text{ and } n > 1\Big}}$

2. ${\Big{x = \dfrac{n - 1}{n - 2}, n ∈ N \text{ and } n > 2\Big}}$

3. ${\Big{x = \dfrac{n}{n + 1}, n ∈ N \text{ and } 1 < n < 2\Big}}$

4. ${\Big{x = \dfrac{n}{n + 1}, n ∈ N \text{ and } 1 ≤ n < 4\Big}}$