A number is selected at random between 20 and 30, both numbers inclusive. Find the probability that the number is a prime

A.
(frac{2}{11}) 
B.
(frac{5}{11}) 
C.
(frac{6}{11}) 
D.
(frac{8}{11})
Correct Answer: Option A
Explanation
Possible outcomes are 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30. Prime numbers has only two factors
itself and 1
The prime numbers among the group are 23, 29. Probability of choosing a prime number
= (frac{text{Number of prime}}{text{No. of total Possible Outcomes}})
= (frac{2}{11})