What is the probability that an integer selected from the set of integers (20, 21, …., 30) is a prime number?
-
2/11
- 5/11
- 6/11
- 9/11
- 2/3
The correct answer is: 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) = \(\frac{2}{11}\)