What is the probability that an integer selected from the set of integers (20, 21, …., 30) is a prime number?
-
A.
2/11 -
B.
5/11 -
C.
6/11 -
D.
9/11 -
E.
2/3
Correct Answer: Option A
Explanation
S = {20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30}
n(S) = 11
P = {23, 29}
n(P) = 2
Prob(P) = (frac{2}{11})