4.3 Independence & Causality

Independent vs. Disjoint


Can two events be both disjoint and independent?

Exercise 1

Events \(A\) and \(B\) are disjoint if \(A\cap B=\emptyset\) and they are independent if \(\Pr[A\cap B]=\Pr[A]\Pr[B]\). If \(A\cap B=\emptyset\), then since \(\Pr[\emptyset]=0\), we need either \(\Pr[A]=0\) or \(\Pr[B]=0\) for them to be independent as well.