1. Section 1

1.29. Explore 3

Mathematics 20-3 Module 2

Section 1: Simple and Compound Interest

 

Self-Check 1
  1. Complete the following table for compound interest investments using the Rule of 72. The first example, 4%, is completely done for your reference.

    Interest Rate Doubling Time Your Calculation
    4% 18 years 72 ÷ 4 = 18
      24 years  
    12%    
    0.09    
    0.02    
      8 years  
        72 ÷ 6 = 12

    Answer

  2. Karl has invested $1000 in a compound-interest bond earning interest at the rate of 0.024 per annum. Karl applied the Rule of 72 as follows.

    72 ÷ 0.024 = 3000

    At that rate, Karl says it will take 3000 years to double his investment. Is Karl correct? Why or why not? Answer

glossary

It is now time to add new math terms to Mathematics 20-3: Glossary Terms.

 

In this lesson the new term you will add is

  • Rule of 72

formula sheet

At this time, you may want to add the Rule of 72 formula to your Formula Sheet.