Question

If P(A or B) =0.8, P(A)=0.2, P(A & B)=0.15 find P(B)

Answer 1

isn't it

\[P(A or B) = P(A) + P(B) - P(A & B)\]

so substitute the values and solve for P(B)

Answer 2

0.2 + P(B)-0.15?

Answer 3

well its

0.8 = 0.2 + P(B) - 0.15