Two room heaters, one rated "400 W, 220 V" and the other "800 W, 220 V", are connected in parallel to a 220V mains supply. The heaters are switched on for 3 hours each day for a 30-day month.
a. (i) Calculate the electrical energy consumed by the two heaters together in the entire month, expressing your answer in kilowatt-hour.
b. (ii) If electricity costs Rs 6 per kWh, find the total monthly cost of running both heaters.