Use the following information:

U = x is a natural number less than 20

A = x is an odd natural number less than 16

B = x

(Note: The prime numbers less than 20 are 2, 3, 5, 7, 11, 13, 17, and 19.) Find the cardinality of each set.

Answer:

n (A'∪ B)

n (U) = 20 n (A) = 8 n (B) = 5 n (A'∪B) = 15

Step-by-step explanation:

For these sets, it is easy enough to list the elements and count them.

U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}

n (U) = 20

A = {1, 3, 5, 7, 9, 11, 13, 15}

n (A) = 8

B = {7, 11, 13, 17, 19}

n (B) = 5

A'∪B = {2, 4, 6, 7, 8, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20}

n (A'∪B) = 15