A loan shark made a loan of $100 to be repaid with $120 at the end of one month. What was the annual interest rate?  Choose one.
A) 210% B) 220% C) 230% D) 240% E) None of these
Explanation:   r=I/PT   Answer: 240%
<result>D</result>
A loan shark made a loan of $100 to be repaid with $120 at the end of one month. What was the annual interest rate?