An unsolvable Chinese math exam question has left the Internet slightly bemused, but others are hailing its approach to critical thinking.

The question, photographed from a grade five exam paper for 11-year-olds, was posted on the Chinese social media site Weibo. It asks: “If a ship had 26 sheep and 10 goats onboard, how old is the ship’s captain?”

It prompted a range of confused responses from children attempting to answer it. One gave up, saying: “The captain’s age is… I don’t know. I can’t solve this.” Others said:

“The captain should be at least 18 years old because a minor is not allowed by law to operate a vessel.”

“The captain is 36, because 26+10 is 36 and the captain wanted them to add up to his age.”

“The number of the sheep and goats is irrelevant to the captain’s age.”

“The captain is 36 years old. He is quite narcissistic, so the number of animals corresponds to his age.”

Users on Weibo and Twitter questioned whether the school, identified as Nanchong Shunqing Primary School, was right to pose such a question. However, in a statement, the Shunqing Education Department said the test was aimed to examine “critical awareness and an ability to think independently.”

They added that some surveys “show that ordinary primary school students in our country lack the sense of doubt and critical spirit in regard to mathematics.”

As the BBC notes, Chinese education relies heavily on note-taking and repetition. But questions like this encourage creative and critical thinking. On Weibo, one person even came up with a pretty clever answer.

“The total weight of 26 sheep and 10 goat is 7,700kg, based on the average weight of each animal,” they said. “In China, if you’re driving a ship that has more than 5,000kg of cargo you need to have possessed a boat license for five years. The minimum age for getting a boat’s license is 23, so he’s at least 28.”

However, that answer is assuming each sheep or goat weighs more than 200 kilograms (440 pounds) – but they’re really about half that. Presumably, then, the captain would only have to be 23 or over, as they’d just need a boat license.

The education department said it would continue to set such questions in the future. And, well, good for them. The question seems pretty fun and harmless, and surely did spark quite a lot of thinking and discussion.