The method of representation used in the set A = {x | x is an even natural number less than 15} is called

1. Description method

2. Rule method

3. Roster method

4. none of these

The cardinal number of the empty set is

1. 2

2. 1

3. 0

4. none of these

If A = {x : x ∈ N and x is an odd prime number less than 17}, then the cardinal number of A is

1. 8

2. 6

3. 5

4. none of these

{months of a year whose names begin with the letter F} is

1. an infinite set

2. empty set

3. singleton set

4. none of these