Question

If A’ is a complement of A then which of the following is true?
A
P(A) + P(A') = 0
B
P(A) - P(A') = 0
C
P(A) – P(A') = 1
D
P(A) + P(A') = 1​

Answer 1

Answer:

In the case when the events A and B are independent the probability of the intersection is the product of probabilities: P(A · B) = P(A)P(B). Example: The outcomes of two consecutive flips of a fair coin are independent events.

Answer 2

The correct answer is option (d) P(A)+P(A') = 1.

• P(A) denotes the probability of an event A and P(A') denotes the probability of an event A not happening.
• So, the sum of both the probabilities will always be equal to 1, because either an event will happen or it would not happen so the sum of their probabilities will be 1.
• For example, the probability of getting a head = 1/2 and the probability of not getting a head = 1/2. So, the sum of both the probabilities = 1/2+1/2 = 1.