According to the meaning of the question, the quantitative relationship is obtained:

Difficulty+Medium+Basic = 100...①

60×3- (middle +3 radix)+radix = 100

180- intermediate -2 radix = 100

Middle +2 group = 80...②

① ② Subtraction can get:

Difficulty-foundation = 100-80=20 questions

That is, there are 20 more questions than the basic questions.

So the answer is: a lot, 20.