This question written for 14-year-olds has gone viral, with adults around the world struggling to figure it out.
Uhhhhh… pass? (via Facebook)
Once we're out of school, most adults don't want to be tested. We honestly would rather not answer any difficult questions, unless they're about the color of a dress. Still, we like to think we'd be able to keep up.
That's why it's so distressing to find out this mind-bending question was intended for 14-year-olds competing in the Singapore and Asian Schools Math Olympiads (SASMO). It's actually the first time a SASMO question has been leaked before the test, so for all we know, they're all like this. How smart are these kids??
I tried to figure out this question. I thought about it for 45 seconds, and then I smelled burnt toast and had to lie down. And when I got up, I had forgotten how to spell berthday.
Here's an explanation of the solution, provided by Singapore-based tutoring service Study Room:
First we need to figure out if Albert knows the month or the day. If he knows the day, then there is no chance that Bernard knows the birthday, so it must be that Albert knows the month.
From the first statement, we know that Albert is sure that Bernard doesn't know the birthday, so May and June should be ruled out (the day 19 only appears in May and the day 18 only appears in June). In other words, if Albert had May or June, then he cannot be sure that Bernard doesn't know, since Bernard could have had 18 or 19.
Following that statement, Bernard knows that May and June are ruled out.
Then, Bernard is able to know which month it is. So it must be either July 16, August 15 and August 17 (not 14th as then he can't know).
Since Albert subsequently can also be sure of the date, he must know it's July. If it's August, he can't be sure as there is August 15 and 17.
So the answer is July 16.