Example 1:
- If you have an investment with an interest rate of 8%, you can use the rule of 72 to estimate how long it will take for your investment to double.
- Number of years required to double = 72 / 8 = 9 years
- Therefore, approximately every 9 years, your investment will double at an 8% interest rate.


Example 2:
- For a different investment with a 10% interest rate:
- Number of years required to double = 72 / 10 = 7.2 years (approximated to 7 years)
- Hence, at a 10% interest rate, your investment would take around 7 years to double.

Limitations:
- 1. The Rule of 72 is a simplified approximation and doesn't account for variations in interest compounding intervals or changes in interest rates over time.
- 2. It assumes a constant interest rate, which may not reflect the actual fluctuations in real-world financial markets.
- 3. The rule cannot predict investment growth accurately in scenarios with significant market volatility or irregular interest rate patterns.

Conclusion:
The Rule of 72 is a useful tool for estimating how long it takes for an investment to double based on compound interest. Although it provides a rough approximation, it can help individuals gauge the potential growth of their investments and make informed financial decisions. However, for more accurate calculations, it is advisable to consult with financial professionals or utilize advanced investment analysis techniques.