Too Many Questions?

I think it really depends on what the quiz is about. Trivia or general knowledge quizzes are quizzes where you first have to read and then maybe even think about the answer. I think a maximum of 30 isn't bad at all. For quizzes like name all the countries or something like that, I don't have a problem with 200 because you hardly have to think and don't have to read anything. For MC quizzes, 10 are actually enough for me, sometimes I get annoyed when there are 20 questions. In general, I think it's good if a quiz doesn't last 10 minutes. Sometimes that's really nice and you want to get involved in it, but I think 1-5 minutes is actually the best.

A.~25

B.15

C. Sudden Death - ~20

A. 10 min, 25 max

B. 10 min, 15 max

C. Picture quizzes, however many answers for roughly 4-5 even rows of pictures

As someone who mostly focuses on city quizzes, I usually stick to between 50 and 100 answers with few exceptions depending on the region or time period. Feeling these things out can be quite difficult.

i think that generally if the number is on the high end of the spectrum (without being insanely high like the us counties quiz), you feel better even if you get a low percentage cuz you intuitively regard the quiz as "harder"

I think it often depends on what your goal with the quiz is, who is the audience you are catering towards. If you're making a niche topic or a quiz where it's much less about actually being a quiz but showcasing interesting information in the form of a quiz, those are good uses of large amounts of answers. But if you're making something that you actually want a lot of people to take, something easily digestible to the general audience, less is best.