(a) p(E or F) = apply the general formula = p(E) + P(F) - p(E and F) =
= now substitute the given data = 0.6 + 0.4 - 0.15 = 0.85. ANSWER
(B) p(E^c) = the complement to p(E) = 1 - p(E) = 1 - 0.6 = 0.4. ANSWER
(C) the set ( E and F^c) consists of those elements of E that do not belong to F.
In other words, ( E and F^c) is E \ (E and F).
Therefore, p(E and F^c) = p(E) - p(E and F) = 0.6 - 0.15 = 0.45. ANSWER