If A and B are independent events with PA 070 and PA Union B

If A and B are independent events with P(A)= 0.70 and P(A Union B)= 0.23 then, P(B) must must equal

Solution

for independece, P(A)*P(B) = P(A and B)

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

0.23 = 0.7 + P(B) - 0.7 P(B)

-0.47 = 0.3 P(B)

P(B) = -1.5667

This is not possible. Please verify if the question is correct.