Question

Let two events A and B be independent. Knowing P(A)=0.8 and P(A+B)=0.93. Calculate the probability P(B).

Answer 1

Hello,

P(B)=0.65

Explanation:

If P(A+B) means P(A∪B)=0.93 then you may read below.

Let's say x=P(B)

A and B being independent, P(A∩B)=P(A)*P(B)=0.8*x

Since P(A∪B)=P(A)+P(x)-P(A∩B) ,

0.93=0.8+x-0.8*x

0.2*x=0.13

x=0.65