For exercises 51–60, use the following information:
u = {x | x is a natural number less than 20}
a = {x | x is an odd natural number less than 16}
b = {x | x is a prime number greater than 5}
(note: the prime numbers less than 20 are 2, 3, 5, 7, 11, 13, 17, and 19.) find the cardinality of each set.
answer
58.
n(b′)