Problem: what is the compound interest on rs . 8500 at 7.5 % p . a . compounded half - yearly for 2 1 / 2 years .
Rationale: "compound interest : a = p ( 1 + r / n ) nt a = 10 , 217.85 c . i . > > 10 , 217.85 - 8500 > > rs . 1717.85 answer : b"
annotated_formula: multiply(8500, subtract(power(divide(add(divide(7.5, const_2), const_100), const_100), multiply(2, const_2)), const_1))