21. If P(E) = 0.9 and P(F) = 0.8, show that P(EF) ≥ 0.7. In general, prove Bonferroni's inequality, namely,
P(EF) ≥ P(E) + P(F) - 1.
Prove Bonferroni's inequality firstly.
P(E U F) = P(E) + P(F) - ...
This solution is comprised of a detailed explanation to prove Bonferroni's inequality.