A={7,11,14,23,27} B={6,11,15,23,26,29} C={11,16,25,28,36} A пересечение B и отнять C

(A ∩ B) / C = ({7, 11, 14, 23, 27} ∩ {6, 11, 15, 23, 26, 29}) / {11, 16, 25, 28, 36} = {11, 23} / {11, 16, 25, 28, 36} = {23}