(i) If A and B are two complementary events then what is the relation between P(A) and P(B)? (ii) If the probability of happening an event A is 0.46. What will be the probability of not happening of the event A?
(i) If A and B are two complementary events then what is the relation between P(A) and P(B)? (ii) If the probability of happening an event A is 0.46. What will be the probability of not happening of the event A?

Solution:

(i) Two complementary events, taken together, include all the outcomes for an experiment and the sum of the probabilities of all outcomes is 1.

P(A) + P(B) = 1

(ii) P(A) = 0.46

Let P(B) be the probability of not happening of event A

Then we know that,

P(A) + P(B) = 1

P(B) = 1 – P(A)

P(B) = 1 – 0.46

P(B) = 0.54

Thus, the probability of not happening of event A is 0.54