An employee receives a monthly salary that increases in arithmetic progression. Her salary in the first month is ₹50 000. At the end of 12 months, the total amount she has received is ₹7 65 000.
(i) Find the fixed monthly increment in her salary.
(ii) Determine her salary in the 20th month.
(iii) Calculate the total salary she will receive in the first 24 months.