IF P(A)=40%,P(A OR B)=60%,P(A AND B)=30% WHAT IS P(B)

Answer 1

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

everything except P(B) is given
sub in the values, make sure to change the percents to decimals
e.g. 60% = .6