Neco 2020 Computer Studies Question 30

A desktop computer contains the following components and their power consumptions at full load:\n\n- CPU: 95 W\n- GPU: 150 W\n- Motherboard: 50 W\n- HDD (2 units): 10 W each\n- SSD: 5 W\n- RAM (4 sticks): 3 W each\n- Cooling fans (3 units): 2 W each\n\nWhen the system operates at 85 % load for 5 hours per day, the CPU and GPU scale linearly with load (i.e., at 85 % load they consume 0.85 of their full‑load power), while all other components keep their full‑load power. During the remaining 19 hours the system is idle at 30 % load, where the CPU uses 30 W and the GPU 45 W, with other components unchanged.\n\n(a) Calculate the total energy consumption in kilowatt‑hours for a 30‑day month.\n(b) Determine the minimum recommended wattage of the power‑supply unit, allowing a 20 % safety margin over the maximum power draw.\n(c) If each cooling fan supplies 30 CFM of airflow and the total heat to be removed equals the total power at full load (assume 1 W = 3.412 BTU / h), and a fan can remove heat at a rate of \(1.08 \times \text{CFM} \times 20\) BTU / h (20 °F temperature rise), decide whether the three fans are sufficient.\n\nProvide the three results respectively: energy (kWh, one decimal), PSU rating (W, nearest whole number), and "sufficient" or "insufficient".