rameshchandra wrote:
Answer : 1/30
Step-by-step explanation:
Since the experiment has only 3 events, therefore the sum of there probabilities should be 1.
P(A) + P(B) + P(C) = 1 ---------- Eq 1
Events A and B are mutually exclusive, therefore
P(A) + P(B) = 0.7 --------------- Eq 2
Events B and C are independent events, therefor
P(B) * P(C) = 0.2 ---------------- Eq 3
On substituting Eq 2 in Eq 1, we get
0.7 + P(C) = 1
P(C) = 0.3
Now replace the value of P(C) in Eq 3
P(B) * 0.3 = 0.2
P(B) = 2/3
Now replacing the value of P(B) in equation 2, we get
P(A) = 7/10 - 2/3
P(A) = 1/30 and that is the answer.
But equation (i) is only true if all A, B and C are mutually exclusive,
It is true that A and B are mutually exclusive, but B and C are not, also we dont know anything about the relationship between set A and C,
So I think that your answer is flawed.