A math problem for primary school students in China sparked heated controversy online, with parents offering four different answers already. What is your answer to the following question?

The answers given by parents include 19, 30, 20 and 16. In the last equation, the cat does not wear the whistle, which could make a difference to the answer. And the correct answer is 16. Did you work it out?

Most of the Chinese parents complain that they are tortured by their children’s math homework, with math questions like the above “full of trap,” Liaoning Daily reported.

“I feel deeply sad when I think of the children having to face such kind of math problems every day. Poor kids! Primary school should put more emphasis on improving children’s practical skill, instead of giving them such tricky questions,” said one mother.

However, not everyone is on board.

A teacher in Shenyang, Northeast China’s Liaoning Province said that the above math question is quite typical in primary school math competition, in bid to examine whether children have the ability to pay attention to both the whole and the part.

“Parents shouldn’t judge on the math question just because they fail to notice the detail in the question,” said the teacher.

The question can also teach children not to go to the conclusion easily without thinking seriously, the teacher noted.

There are more pupils’ math questions. Can you work them out?

How many triangles are there in the above picture?