The gross energy requirement, to reduce a very large feed of coal to such a size that 80% of the product passes through a 100 µm screen, is 13 kWh per ton of feed. In a process, 250 tons h⁻¹ of coal is crushed. The range of feed sizes is such that 80% of the feed passes through an opening of 100 mm. The product size range is to be such that 80% of the product passes through an opening of 25 mm. According to the Bond's law, which one of the following is the power consumption (in kW)?