I came across this quiz question in a forum today. I would like to ask for your opinion of this notorious mathematics question, and also, to share.
This question came out in Singapore's PSLE examination 2005. Basically, PSLE is one of the most important exams of one's life in Singapore. It literally determines your future, to a huge degree. How did such a question slip past the examiners, we would never know.
As for my real question, is that, is there a valid answer to this question ultimately? I mean, there can be more then one answer, but can it be argued in such a way, that one answer can ultimately be proven to be true?