A math question reportedly designed for 6-year-old school children has the Internet buzzing after bewildered parents struggled to solve the difficult problem.
The confusion began after mother Louise Bloxham, who lives in Bristol, England, snapped a picture of the problem and posted it on Twitter, The Sun reports.
"Have you seen this one?" she wrote. "Year 2!!"
The question reads: "There are some people on a train. 19 people get off the train at the first stop. 17 people get on the train. Now there are 63 people on the train. How many people were on the train to begin with?"
After arriving at several different answers, the Twitter community determined that there were 65 people on the train to begin with.
Starting with the current number of passengers on the train, 63, you subtract the 17 who just got on, leaving you with 46.
You then add the 19 people who got off the train back into the equation, arriving at 65 — the original number of passengers.
To confuse matters even further, Bloxham then posted on Twitter that, according to the teachers who gave the test, the correct answer is actually 46.
This was concluded to be false, and the issue was settled with all agreeing that 65 is correct.
When the dust settled, a number of parents expressed indignation that such a complicated question was given to 6-year-old children.
"That's abstract thinking which hasn't developed in children that age, still at concrete concepts," one father wrote, according to the Sun.
"Children who can do math but struggle to read have no chance, whatever the answer," another parent wrote. "Sickening."
The occasion calls to mind another viral math problem that confounded the Internet in 2015. Presented to 14- and 15-year-olds in Singapore, a question about the birthday of a girl named Cheryl had people all over the world wondering whether it was even fair, according to BBC News.
Henry Ong, the director of the organization that came up with the problem, explained the decision to include the confusing question.
"We are not saying this problem is for every student," he said, according to BBC. "But if these kinds of problems can be used to stretch the better students to sharpen their analytical power, why not?"