Problem: what is the rate percent when the simple interest on rs . 2000 amount to rs . 320 in 4 years ?
Rationale: "interest for 1 year = 320 / 4 = 80 interest on rs 2000 p / a = 80 interest rate = 80 / 2000 * 100 = 4 % answer : c"
annotated_formula: divide(multiply(const_100, 320), multiply(2000, 4))