12 of the students in a Geometry class passed a Geometry test. If these students are 80% of all the students in the class, how many students are in this Geometry class?

Rachel is studying the population of a particular bird species in a national park. she observes every 10th bird of that species that she can find in the park. her conclusion is that the birds living in the park who belong to that species generally feed on insects. rachel's sample is . based on the sample she picked, rachel's generalization is