Three appliances are used in a student’s room during one evening: a ceiling fan rated 75W is run for 6h, a table lamp rated 40W is switched on for 3h, and an electric iron rated 600W is used for 20min. Answer the following:
(i) Calculate the total electrical energy consumed by all three appliances in that evening, expressing your answer in kilowatt-hour.
(ii) Suppose the total electrical energy available for that evening is restricted to 1.5kWh. If the usage times of the lamp and the iron remain unchanged, find the maximum duration for which the ceiling fan can be operated without exceeding the available energy limit.