Answer:
10 seventh-grade boys and 10 seventh-grade girls
25 seventh-grade students
Explanation:
Sampling
This is a common statistics practice, when we want to study something from a population, we find a sample of this population. This sample has to be representative.
In this question:
Students in the seventh grade prefer to visit the aquarium or the science museum for their end-of-year trip.
So the sample would have to contain only students from the seventh grade. So the correct options are:
10 seventh-grade boys and 10 seventh-grade girls
25 seventh-grade students