Write the cardinal number of each of the following sets:

1. A = {0, 1, 2, 4} n(A) = ____

2. B = {-3, -1, 1, 3, 5, 7} n(B) = ____

3. E = {Natural numbers between 15 and 20} n(E) =___

4. D = {3, 2, 2, 1, 3, 1, 2} n(D) = ____

5. F = {whole numbers from 8 to 14} n(F) = ____

6. C = { } = n(A) = ____