3 ms·

Why couldn't it be in August? For example if B was told 15, he could still do the same analysis, eliminate May and June and come to that conclusion.

• thedufer 12y ago
  In the last line, A notes that B knowing means that A now knows. This is only possible if it is July, since knowing the month isn't enough to distinguish between the two possible dates in August.
  • ramy_d 12y ago
    This is correct. Although this is how we solve the problem, how did B know? that's where problems like these bug me.
    • detcader 12y ago
      B knows because B had the information "16th", and "16th" is unique among the July and August dates.
      • cafard 12y ago
        Quite, but B could have easily known "15th" or "17th" for all that A knows in this particular part of the story.
        • rwbhn 12y ago
          Nope, A knows July from the beginning - which rules those out. We, the readers, don't know that until A's final stmt.