Question: An individual is to select from among n alternatives in an attempt to obtain a particular one. This might be selection from answers on a multiple choice question, when only one is correct. Let A be the event he makes a correct selection, and B be the event he knows which is correct before making the selection. We suppose P (B) = p and P (A|Bc) = 1/n. Determine P (B|A); show that P (B|A) ≥ P (B) and P (B|A) increases with n for fixed p.