Question

If P(A)=0.4, P(A and B)=0.2,and P(A or B)=0.5, What is P(B)

Answer 1

`\boxed{\ P(B)=0.3 \ }`

Explanation:

Hi,

We know that

P(A or B)=P(A)+P(B)-P(A and B)

so P(B)= P(A or B) - P(A) + P(A and B)

so

P(B) = 0.5 - 0.4 + 0.2 = 0.3

thanks