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

1. {4}

2. {0, 4}

3. {0, 2}

4. {2, 4}

If set A = {x : x ∈ N, x = n - 3, n ∈ N and n < 3}, then set A is :

1. {-3, -2, -1, 0, 2}

2. { }

3. {-3, -2, -1}

4. {0, -1, -2, -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