Problem 386
Marla earned $400 interest over 2 years on a $4,000 investment. Jovita earned $960 interest over 4 years on her $6000 investment. Who had the higher rate of interest? Explain.
Solution
Interest for Marla (r) = 
= 
= 5%
Interest rate for Jovita (r) = 
= 
= 3%
Now we can see that Marla has higher interest rate.