Question

Use the Rule of 72 to estimate how long it will take for India, Spain, and South Africa to double their standards of living.

Short answer

India - 13.11 years, Spain - 25.17 years, South Africa - 1,200 years

Step-by-step solution

Step 1. Introduction 

The rule of 72 is a rule of thumb used to estimate the approximate time it would take a variable to double its value. It is generally used to estimate the expected time for an investment to double in value. Though it can also be used for other economic indicators.

Step 2. Explanation

The estimated time to double the standards of living can be obtained as,

$$\begin{gathered} \text{Estimate Time}=\frac{72}{\text{GDP per capita growth}} \\ Forindia \\ =\frac{72}{5.49}=13.11 \\ Forspain \\ =\frac{72}{2.86}=25.17 \\ ForSouthAfrica \\ =\frac{72}{0.06}=1200 \end{gathered}$$