Overall Strategy¶

When Cheryl tells Albert 'May' then he knows there are three possibilities, but we (the puzzle solvers) don't, because we don't know what Cheryl said. So what can we do? We will consider all of the possible dates, one at a time. For example, first consider 'May 15' . Cheryl tells Albert 'May' and Bernard '15' , giving them the lists of possible birthdates shown above. We can then check whether statements 3 through 5 are true in this scenario. If they are, then 'May 15' is a solution to the puzzle. Repeat the process for each of the possible dates. If all goes well, there should be exactly one solution.