Bill rows his boat at 10 miles per hour. he rowed 20 miles down a stream and then rowed back to his starting point. the stream was flowing at 2 miles per hour. how many hours and minutes did it take him to complete his trip.

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