I'm trying to guess what you meant. I'm guessing you had 3 overlapping sets (circles), labeled A,B,C with 7 regions numbered 1 to 7.P(A∪B) = P(1) + P(4) + P(2) + P(5) + P(3) + P(6) = 0.1 + 0.05 + 0.1 + 0.05 + 0.1 + 0.5 = 0.9 P(4) = 0.05 (That's given above. Don't know why they would ask that!!!) P(A∩B) = P(2) + P(5) = 0.1 + 0.05 = 0.15 P(A∪A) = P(A) = P(1) + P(2) + P(4) + P(5) = 0.1 + 0.1 + 0.05 + 0.05 = 0.3 ------------------------------------------------------------ I have no idea what the rest of what you wrote meant. I can't even guess. A=1,5,6 but A isn't those regions! B=4,7 but B isn't those regions! A/B=2,3 Is that the difference of A minus B? If so that is not 2,3. Sorry, We have no idea of what that could mean. Edwin