Story was updated on April 17, 2015
SINGAPORE - A mathematics question has been making the rounds on Facebook and stirring up debate.
The logic question was shared by TV presenter Kenneth Kong on Facebook, and has been shared more than 2,000 times since Saturday.
"This question causes a debate with my wife... and it's a P5 question," he wrote.
A debate about the answer was conducted in the comments thread under the post.
The post also caught the attention of people outside Singapore.
The Australian Federation of International Students shared it on its Facebook page, and it was posted on reddit.com and Philosophy Forums.
Singapore's maths syllabus - which has a strong focus on problem solving and using model drawings - has been adopted in a number of South-east Asian countries, the United States and even South America.
However, Singapore parents have raised concerns at times that pupils are being placed under tremendous stress in school.
Can you solve this problem?
Correction note: An earlier version of the story, which cited a Facebook post, said the logic question was a Primary 5 mathematics question. It has since been clarified that it was a Math Olympiad question for Secondary 3 students.