This question was part of a Singapore and Asian Schools Math Olympiad test paper. For all the brainiacs here, see if you can solve this. 
Can you solve the maths question for Singapore schoolkids
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Can you solve the maths question for Singapore schoolkids

To clear up any ambiguity, Cheryl tells Albert the month in which her birthday falls, and she tells Bernard the day?s number.
In other words, Albert is told either May, June, July or August. Bernard is told either 14, 15, 16, 17, 18 or 19.
Here's link to the answer.