Problem: the average monthly salary of 20 employees in an organisation is rs . 1400 . if the manager ' s salary is added , then the average salary increases by rs . 100 . what is the manager ' s monthly salary ?
Rationale: "explanation : manager ' s monthly salary rs . ( 1500 * 21 - 1400 * 20 ) = rs . 3500 . answer : e"
annotated_formula: subtract(multiply(add(1400, 100), add(20, const_1)), multiply(1400, 20))