>Assuming that every question in this 20-question test has only 1 right answer and you choose to answer each question randomly, what is the chance that you're so bad that you only get 4 questions right or less?

They probably mean for you to assume that 1) each question has 5 answer choices, and 2) you select one of them with equal probability. But given that this is question #2, assumption (1) is kind of a guess, and (2) should be explicitly stated... (the answer btw has to do with the binomial distribution - and you definitely need some heavy arithmetic, so are they testing your gut instinct?)

The messed up question I was referring to, and I think bloaf was referring to, is a later one, the second one involving random answers:

> Assuming that every question in this 20-question test has only 1 right answer and you choose to guess the answer of each question randomly, then in terms of the number of correctly-guessed answers, approximately 68% of them will fall between:

> A. 2.2 and 5.8

> B. 0.8 and 7.2

> C. 6.8 and 12.5

> D. 7 and 13

> E. None of the above

Another messed up question was the one early on asking whether the dot product operator is "associative/commutative on addition" or not. That's not a thing that actually means something.

I answered none of the above precisely because associativity doesn't apply to an operator that maps 2 vectors to a scalar. But it still felt wrong.

Oh, I was parsing the responses like "(Non-associative, commutative and distributive) on addition". And no, the dot product is not commutative on addition. But it's meant to be "Non-associative, commutative and (distributive on addition)".