Question

A city is divided by a river. The portion of the city east of the river covers 25% of the city and has a population density of 28 people/km2. The portion on the west side of the river has a population density of 17 people/km2. Find the population density of the city as a whole.

Answer 1

The answer is 19,75 people / km2

Explanation:

Let's say that the total area of the city is 4 kilometer squares. In that case, the east of the river, which is 25% of the city, is 1 kilometer square. This means that the population is 28 on the east side of the city

The west side of the city is 3 kilometer squares, which means the population is 17 x 3 = 51.

The total population of the city is 51 + 28 = 79 and the total area is 4 kilometer squares. So the population density of the city as a whole is

79 / 4 = 19,75 people per kilometer square.

I hope this answer helps.