If a number is chosen at random from the set of first 20 natural numbers, The probability that it is either an even number or a prime number is?	Answers
A) 15/20
B) 8/20
C) 10/20
D) 17/20
E) 18/20
Explanation:   n(S) = 20   n(Even no) = 10 = n(E)   n(Prime no) = 8 = n(P)   P(EᴜP) = 10/20 + 8/20 - 1/20 = 17/20   Answer is 17/20
<result>D</result>
If a number is chosen at random from the set of first 20 natural numbers, The probability that it is either an even number or a prime number is?