The difference between C.I. and S.I. on an amount of $10,000 for 2 years is $36. What is the rate of interest per annum?
Choose the correct choice from the following options:
A) 5 %
B) 6 %
C) 7 %
D) 8 %
E) 9 %

Rationale: "$ 36 is the interest on the first year of interest . let x be the interest rate . the interest after the first year is 10000 * x . the interest on the first year ' s interest is 10000 * x * x 10000 * x ^ 2 = 36 x = 0.06 the answer is b ."
Answer: B