1) To prove P(E U F) >= 0.8, first express E U F as the union of 2 disjoint events (hint: consider set difference between F and E). Then use theorem 1 from page 404. 2) To prove P(EF) >= 0.4, use inclusion-exclusion principle, then use the fact that P(E U F) <= 1.
--Asuleime 02:17, 9 October 2008 (UTC)
