1 ) Y = {a, b, c, d, e). How many PROPER subsets does the set Y have?
A. 7
B. 15
C. 31
D. 63
2) Which of the following set has the cardinality equals to 4?
A. Set A is the counting numbers less than 4
B. Set B is the set of the letters in the word "looks"
C. Set C is the set of all factors of 4
D. Set D is set of multiples of 4 less than 24​