Mathematical olympiad in the fifth grade of primary school (percentage)

Maximum: 60%, that is, the people who have booked all three kinds are repeated, and the people who have booked all three kinds are repeated at most, so that the people who have booked all three kinds are the most.

At least:1-(20%+25%+40%) =15%, that is, those who have not booked will not repeat, and those who have not booked will not repeat, thus making the number of people who have booked all three at least.

The traditional algorithm is:1-[80%+75%+60%-(80%+75%-1)-(75%+60%-1)-(80%+60%-65438).