The arcs are circles of the same radius offset by 6cm. That makes the white area in one square congruent to a white area in the adjacent square. Two full worth of blue are shaded.
Actually this is a routine question asked of 12-year-olds in our Primary School Leaving Examination. They are trained to employ such heuristic thinking
I should post some tough PSLE questions here. Every other year, a question gets featured in our national media because kids come out of the exam room crying, parents cry foul, and education personnel tell everyone to chillax. It’s all very dramatic haha
Happened here too for 수능, university entrance exam. Some questions end up being too difficult. And because one's whole future sounds depends on a single exam, this can lead to big emotions...
That's a bit of a caricature, but it used to be pretty much like that. Slowly changing though. One of my recent students, not from any of those 4 unis, got hired without a problem by Samsung.