Those quizzes are completely worthless. There's no way 53% of the population doesn't know that. It was probably worded weirdly or set up in a way that tricked people.

Another one that made the rounds recently was the one where they asked people to estimate what percentage of the population is trans, and the median answer was like 20%. There is no way this captures actual beliefs held by real people, it's a number so unaligned with basic reality that the only thing it points to is a flaw in the test.

My working theory is that a good chunk of the interviewees are uncomfortable being asked nerd shit like this and they just say whatever they think will make the game stop.