The population of the world is approximately [tex]5 \times 10^9[/tex] and its area is [tex]4 \times 10^{11}[/tex] square kilometers. Find the number of persons per square kilometer.



Answer :

Sure, let's solve this problem step by step to find the number of persons per square kilometer given the population and the area of the world.

1. Understand the Given Values:
- The world population is approximately [tex]\(5 \times 10^9\)[/tex] people.
- The total area of the world is [tex]\(4 \times 10^{11}\)[/tex] square kilometers.

2. The Formula to Use:
To find the number of persons per square kilometer, you need to divide the total population by the total area. The formula is:
[tex]\[ \text{Persons per sq km} = \frac{\text{Total Population}}{\text{Total Area}} \][/tex]

3. Substitute the Given Values into the Formula:
Here, the total population is [tex]\(5 \times 10^9\)[/tex] and the total area is [tex]\(4 \times 10^{11}\)[/tex]. Substituting these values into the formula gives:
[tex]\[ \text{Persons per sq km} = \frac{5 \times 10^9}{4 \times 10^{11}} \][/tex]

4. Simplify the Expression:
To simplify,
[tex]\[ \frac{5 \times 10^9}{4 \times 10^{11}} = \frac{5}{4} \times \frac{10^9}{10^{11}} \][/tex]

5. Calculate the Powers of Ten:
When dividing exponents with the same base, subtract the exponents:
[tex]\[ \frac{10^9}{10^{11}} = 10^{9-11} = 10^{-2} \][/tex]

6. Combine the Results:
Now, multiply the simplified fraction with the power of ten:
[tex]\[ \frac{5}{4} \times 10^{-2} = 1.25 \times 10^{-2} \][/tex]

7. Convert to Decimal Form:
[tex]\[ 1.25 \times 10^{-2} = 0.0125 \][/tex]

8. Result:
So, the number of persons per square kilometer is [tex]\(0.0125\)[/tex].

To summarize, given the world population of [tex]\(5 \times 10^9\)[/tex] and an area of [tex]\(4 \times 10^{11}\)[/tex] square kilometers, the number of persons per square kilometer is [tex]\(0.0125\)[/tex].