A math problem for students in Singapore has gone viral, and made people around the world crazy, on social media.
In the problem, Cheryl tells her friends Albert and Bernard 10 possible dates for her birthday, and tells Albert her birthday month and Bernard the day. Albert and Bernard have a conversation about what they know, and from that you're supposed to deduce the answer.
Singaporean television presenter Kenneth Kong posted the question to Facebook on Friday, incorrectly saying that the problem was intended for 10- and 11-year-old students.
The Singapore and Asian School Math Olympiad clarified on its Facebook page that the problem was actually part of a contest for high school sophomores and juniors.
"Being Question 24 out of 25 questions, this is a difficult question meant to sift out the better students," wrote SASMO. "SASMO contests target the top 40% of the student population and the standards of most questions are just high enough to stretch the students."
People soon took to Twitter with their frustrations.
“If Cheryl makes it this hard to find out when her birthday is, she's not going to get many gifts,” wrote Twitter user Katie Chrystler.
"The worldwide excitement and curiosity about this problem is very encouraging," Steven Strogatz, professor of applied mathematics at Cornell University told the Huffington Post via email. "It shows that people love to think logically (or at least, to try to think logically), just for the pleasure of it. Even though the problem isn't good for anything, it's still fun to think about."
For those without the mental strength to work through it, see the SASMO solution here.