Problem: if the cost price is 91 % of sp then what is the profit %
Rationale: "sol . sp = rs 100 : then cp = rs 91 : profit = rs 9 . profit = { ( 9 / 91 ) * 100 } % = 9.89 % answer is a ."
annotated_formula: multiply(divide(subtract(const_100, 91), 91), const_100)