Question

Set A is the set of all positive multiples of 2 that are less than or equal to 20. Set B is the set of all positive multiples of 4 that are less than or equal to 20. How many elements are positive multiples of 4 that are less than or equal to 20, but are not positive multiples of 2?

Answer 1

A = {2, 4, 6, 8, 10, 12, 14, 16, 18}
B = {4, 8, 12, 16}

All elements of set B are also elements of set A.

Answer: None.
All multiples of 4 are automatically multiples of 2.