Answer:
90.91 years
Explanation:
If the rate of population of the world was 7.1 billion in 2013, and the observed relative growth rate was 1.1% per year, increase in yearly population = 1.1/100 × 7,100,000,000
= 1.1 × 71,000,000
= 78,100,000
The amount increases by 78.1million every year.
To know how long it will take the population to double.
double of the initial population = 2×7,100,000,000 = 14,200,000,000
Increment per year = 78,100,000
Time it will take for the population to double = 7,100,000,000/78,100,000
= 90.91
≈ 91
This means it will take about 90.91years for the population to double