Given that= Y(multiples of 3 less than 20),find the number proper subset of Y?

Answer 1

Y = {3,6,9,12,15,18} , so 6 of them

number of subsets = 2^6, including the null set and all of the elements

Use the definition of "proper subset" that you learned to finetune the answer.

Answer 2

3,6,9,12,15,18

Answer 3

3,6,9,12,15,19