Problem: if the cost price is 90 % of sp then what is the profit %
Rationale: "sol . sp = rs 100 : then cp = rs 90 : profit = rs 10 . profit = { ( 10 / 90 ) * 100 } % = 1.11 % answer is b ."
annotated_formula: multiply(divide(subtract(const_100, 90), 90), const_100)