2.547 ÷ 6 = 9 1 ... 1 Because if the total score is 546, then the average score is 9 1, and now the total score is 546, then at least one student's score will not be lower than 92.

3. 1999 has 365 days, so 366 people have at least two birthdays on the same day. 183 1 people have at least two birthdays on the same day.

4. Second, there are only six boats because there are seven people. After one person, there is another person.

5. Second, because the number of people in the six ships is as follows: 1, 1, 1, 2, 1 9.

6.2 1 person, because there are 20 boys, 10 girls.