If A = {3, 5, 7} and B = {5, 7, 9}, then n(A ∩ B) is :

1. 6

2. 2

3. 4

4. none of these

If n(universal set) = 80 and n(A) = 50, then n(complement of set A) is :

1. 80

2. 50

3. 30

4. none of these

If set A = {x : x ∈ W and 0 < x ≤ 4}, then set A is equal to :

1. {0, 1, 2, 3}

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

3. {1, 2, 3, 4}

4. none of these

If set P = {factors of 8}, then set P is equal to :

1. {2, 4, 8}

2. {1, 2, 4}

3. {1, 2, 4, 8}

4. none of these