Cody won 64 super bouncy balls playing hoops at the county fair. At school he gave three to every student in his math class. He only has 7 remaining. How many students are in his class ? need algebraic equation too

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