P(A) = 0.2, P(A or B) = 0.5, and P (A and B) = 0.1, find P(B)?


a) 0.7

b) 0.8

c) 0.6

d) 0.4

You're given all the info, just solve for P(B).

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