An employee joins a company at an annual salary of ₹4,20,000. Every year the salary is increased by a fixed amount of ₹24,000.
(i) Obtain, in terms of n, an expression for the salary received in the nth year after joining.
(ii) In which year will the annual salary first reach or exceed ₹7,80,000? Show all steps clearly.
(iii) Calculate the total salary drawn by the employee during the first 12 years of service.