Answer:
975 students
Explanation:
This is a dense question. Let's look at it piece by piece:
1. The ratio of boys to students in the class is 10/25. If there are 25 students and 15 girls, that leaves 10 boys.
2. The question says that the ratio is in proportion of boys to total students in the school. "In proportion" in this case means that if we convert 10/25 to a fraction with numerator 390, the denominator is the amount of students in school.
3. 10x39=390. What you do the numerator you must do to the denominator: 25x39=975.
4. This means 975 students go to the school.