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1. What is the probability that a number selected from numbers 1, 2, 3, ......, 30, is prime number, when each of the given numbers is equally likely to be selected?

A. $\frac{9}{30}$

B. $\frac{8}{30}$

C. $\frac{10}{30}$

D. $\frac{11}{30}$

Solution:

X = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29}
n(X) = 10, n(S) = 30
Hence required probability,

\begin{aligned} = \frac{n (X)}{n (S)} \\ = \frac{10}{30} \end{aligned}

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