Density from area and volume, step by step
Density is how much of something sits in one unit of space.
The question
16,875 people people per sq mi
People per square mile
15 × 15=225 sq mi
16,875÷225=75
75 people per sq mi
- First the area of the land, because the question gives its sides and not its size: 15 × 15 = 225 square miles.
- Density is how much there is in ONE unit, so share the people over the area: 16,875 ÷ 225 = 75.
- So 75 people live on each square mile. That is the density — a count for one unit of area, which is why it can be compared between counties of different sizes.
How it works.
- 01
First the area of the land, because the question gives its sides and not its size: 15 × 15 = 225 square miles.
- 02
Density is how much there is in ONE unit, so share the people over the area: 16,875 ÷ 225 = 75.
- 03
So 75 people live on each square mile. That is the density — a count for one unit of area, which is why it can be compared between counties of different sizes.