Answer:
a) 2.1 billion tons/yr
b) 10.5 billion people
Explanation:
Given:
Total arable land = 1.4 billion
Grain produced by each hectare of land = 1 and 2 tons annually
therefore,
The average Grain produced by each hectare of land = [tex]\frac{\textup{1+2}}{\textup{2}}[/tex] = 1.5 tons/yr
Therefore,
The total grain produced annually
= average Grain produced × Total arable land
= 1.5 × 1.4 billion
= 2.1 billion tons/yr
b) Sufficient grain for each people = 200 kg
Now,
1 ton = 1000 kg
thus,
2.1 billion tons = 2.1 × 10⁹ × 1000 kg = 2.1 × 10¹² kg
The number of people Earth can support = [tex]\frac{\textup{ total grain produced annually }}{\textup{Sufficient grain for each people}}[/tex]
or
The number of people Earth can support = [tex]\frac{\textup{ 2.1}\times10^{12}}{\textup{200}}[/tex]
or
The number of people Earth can support = 10.5 × 10⁹ people
= 10.5 billion people
