x, y, and z are all unique numbers. If x is chosen randomly from the set {10, 11} and y and z are chosen randomly from the set {20, 21, 22, 23}, what is the probability that x and y are prime and z is not?	Choose the correct choice from the following options
A) 1/5
B) 3/20
C) 1/8
D) 3/10
E) 1/10
P(x is prime) = 1/2   P(y is prime) = 1/4   If y is prime, then z is not prime since y and z are unique.   Then the probability is 1/2*1/4 = 1/8   The answer is 1/8.
<result>C</result>
x, y, and z are all unique numbers. If x is chosen randomly from the set {10, 11} and y and z are chosen randomly from the set {20, 21, 22, 23}, what is the probability that x and y are prime and z is not?