a. A trainee is paid ₹18,000 in the first month. The stipend rises by ₹1,000 each month until it reaches ₹24,000, after which it remains fixed for the rest of a 15-month training programme.
(i) For how many months does the stipend rise?
b. (ii) Find the total stipend paid to the trainee over the entire 15-month programme.