Mathematics

What is the probability that an integer selected from the set of integers (20, 21,…

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})