Question 861169
You need to find P(A intersection B).
 P(A U B)=P(A)+P(B)-P(A int B)
0.6=0.3+0.4-P(A int B)
0.6=0.7-P(A int B)
P(A int B)=0.1
So now looking at the conditional probabilities,
P(A|B)=P (A int B)/P(B)=0.1/0.4=1/4
P(B|A)=P(A int B)/P(A)=0.1/0.3=1/3