Question

A fair die is thrown once. What is the probability that either an even number or number greater than three will turn up?

Answer 1

Probability to get an even number = P(A) = 3/6 = 1/2

Probability to get a number greater than 3 = P(B) = 3/6 = 1/2

Prob. of getting even number greater than 3 = P (A ∩ B) = 2/6 = 1/3

Probability that either an even number or a number greater than 3 will turn up = P(A U B)

= P(A) + P(B) - P(A ∩ B)

= 1/2 + 1/2 - 1/3 = 1 - 1/3 = 2/3