7.1. In 7a class, $52\%$ are girls. All students in the class can line up in such a way that boys and girls alternate. How many students are in the class?
Answer: 25 students. Solution: Considering that there are more girls than boys in the class, from the condition of alternation, we get that there are exactly one more girl than boys. Therefore, one person constitutes $52-48=4 \%$ of the class size. Thus, the number of students in the class (i.e., $100 \%$) is $100 / 4=25$ people.