A. 14
B.0.43
C.0.75
D.0.59
Does anyone know the answer to this question?
2 Answers

Let’s recall some rules of probability.
P(A n B) = P(A)P(BA) (General Multiplication Rule)
P(A U B) = P(A) + P(B) – P(A n B) (General Addition Rule)
So we can first find P(A n B) first using the General Multiplication Rule.
P(A n B) = (0.4)(0.35) = 0.14
Then we can find P(B) using the General Addition Rule.
0.69 = 0.4 + P(B) – 0.14
0.69 = P(B) + 0.26
So P(B) = 0.69 – 0.26 = 0.43. The answer is B.

If P(A) = 0.4, P(B  A) = 0.35, P(A È B) = 0.69, then P(B) =