Answer:
Step-by-step explanation:
We are to assume the earth is a sphere and the radius has been given in the question which is 3959 miles
Area of a sphere = 4*pi*r^2
Where pi= 22/7 (constant)
r= radius
Area= 4*22/7*3959^2
=4*22/7*15673681
=1379283928/7
=197040561.14 square mile
=197040561.14 mi^2
Total area of the earth has been solved as 197040561.14 mi^2 and 20 percent of this surface area is suitable to live on.
We calculate the 20% thus:
20/100 * 197040561.14 mi^2
=3940811222.8/100 mi^2
=39408112.228mi^2
There are approximately 7.7 billion people on earth that will live on the suitable land with an area of 39408112.228mi^2
Each person in the world will have square mile of
39408112. 228 mi^2 / 7.7billion persons
=39408112.228/7700000000
=0.0051179367mi^2 per person
Approximately, 0.00512mi^2/person (option C)
Check the attachment for better mathematical expressions
