 Go back to the truth table. You are wondering whether if \(A, B\). Assume \(A\). That is, ignore lines 3 and 4 in which \(A\) is false. Ask yourself about the relative probabilities of lines 1 and 2. Suppose you think line 1 is about 100 times more likely than line 2. Then you think it is about 100 to 1 that \(B\) if \(A\).