10. Xiao Ming and Xiao Hua are in Class 6 (1), and the number of students in the class is between 20 and 30, with each student having a unique birthday. Xiao Ming says, “The number of students older than me is twice the number of students younger than me,” and Xiao Hua says, “The number of students older than me is three times the number of students younger than me.” How many students are there in the class?
According to Xiao Ming and Xiao Hua, the number of students in Class 6 (1) minus 1 is a multiple of 3 and also a multiple of 4. $[3,4]=12$, so the class has $12 \times 2+1=25$ students.