The compound interest earned on a sum for the second and the third years are $1400 and $1512 respectively. What is the rate of interest?  Choose the correct choice from the following options.
A) 5 %  B) 6 %  C) 7 %  D) 8 %  E) 9 %

Rationale: "1512 - 1400 = 112 is the rate of interest on $ 1400 for one year . the rate of interest = ( 100 * 112 ) / ( 1400 ) = 8 % the answer is d ."
Answer: D