Question

A die is thrown. Let A be the event that the number obtained is greater than 3. Let B be the event that the number obtained is less than 5. Then P(A ∪ B) is

(a)2/5 

(b)3/5 

(c) 0 

(d) 1

Answer 1

(d) : A = {4, 5, 6}
Also B = {1, 2, 3, 4}
We have A ∪ B = {1, 2, 3, 4, 5, 6} = S
Where S is the sample space of the experiment of throwing a die. P(S) = 1, for it is a sure event.
Hence P(A ∪ B) = 1