I think you're reading too much into it - the point actually is the puzzle. Some people find it really fun to have their mind challenged, even in small ways lik

I think you're reading too much into it - the point actually is the puzzle. Some people find it really fun to have their mind challenged, even in small ways like this. It's the same idea as picking up a sudoku every day. The reason that such a low percentage of people got this right is probably the most obvious one: Only those who have a math background (so that they encountered actual problems like this), or who have a natural impulse to be a little OCD about obtaining and verifying the answer, will be likely to get it right the first time. That doesn't mean that both they and those who got it wrong can't have fun with it.