My question is very hard for me

Question

The population density must be a maximum of 10 animals per sq mile. In a rectangular wildlife preserve measuring 25 miles by 20 miles, wildlife biologist counted 3840 of the animals. Is there enough areal for all of the animals. Why or why not  

Answer 1

The area of the preserve is (25)(20) = 500 sq mi

 

Population density = (number of animals)/area = 3840/500

 

                                                                                    = 7.68 animals/mi²

 

Since the population density is below the maximum of 10 animals per square mile, there is enough area for all of the animals.  

Answer 2

It's important to think as concretely as possible what population density means, which you can do several ways. Consider a few examples: If the area were 2 square miles, then more than 20 animals would be too many. Similarly, if the area is 100 square miles, then 1000 animals or fewer would be acceptable. Do you see the pattern?: Calculate the number of square miles. Ten times that number is the maximum number of animals that can live on the land.

 

The area for this problem is (25 miles)x(20 miles) = 500 square miles. Therefore, the land can support a maximum of 5000 animals. The question is whether 3840 animals can survive, so the answer is yes because 3840<5000.