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′)

  15

Step-by-step explanation:

We assume your "natural numbers" are positive integers. (Some authors also include zero.)

n(B) = 5

n(U) = 20

n(B') = 20 -5 = 15

10/60

step-by-step explanation:

if you divide 10 by 60 the answer is 0.166666 while if you divide or solve the other problems it equals 0.6

a = 3.14

b = 18

c = 18/5 or 3.6 or 3 3/5

step-by-step explanation: