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Inclusion and exclusion of primary school mathematics
1. Because the wrong question accounts for the total number of 1╱4, and the wrong question accounts for the total number of 1╱6, so the total number of this question should be a common multiple of 4 and 6, (that is,12:/kloc-0. ...

Because B made three mistakes, and neither of them made more than three mistakes (1╱6 of the total), the total number of mistakes did not exceed 3/( 1╱6)= 18, so the total number of mistakes was 12.

Further calculation, A and B also did 9 right questions, 3 wrong questions and 2 wrong questions, so there were 8 right questions.

2.Total-nothing = at least one: 25-6= 19.

Yes-cycling = swimming or skating: 19- 17=2.

Swimming or skating-swimming = skating only: 2- 13

So, two people can swim and skate.

Similarly:

Yes-swimming = riding or skating: 19- 13 = 6.

Yes, I can skate = I can ride a horse or swim: 19-8 = 1 1

Explain that examinees can do two sports.

What are the excellent conditions? There won't be at least two, will there?

If three will be excellent, the title condition has already said that no one will have three, and Excellence is 0.

If two are excellent, there are 2+6+ 1 1= 19.

3.28- 17-8=3 people

4.

Party A * * * has seen at least 75+60- 100=35 copies of Party B, and Party A * * * has at least 60+52- 100= 12 copies, and at least 75+52-65433 copies.