Problem: on a sum of money , simple interest for 2 years is rs 660 and compound interest is rs 696.30 , the rate of interest being the same in both cases .
Rationale: explanation : difference between c . i and s . i for 2 years = 36.30 s . i . for one year = 330 . s . i . on rs 330 for one year = 36.30 so r % = \ frac { 100 * 36.30 } { 330 * 1 } = 11 % answer : d
annotated_formula: multiply(divide(multiply(subtract(696.3, 660), 2), 660), const_100)