Final answer:
The correct option is C. For professional cleaning of ventilation hoods, the frequency depends on the amount and type of cooking, with commercial kitchens requiring monthly to annual cleanings based on usage, while residential hoods should generally be cleaned at least annually. For calculating the expectation of a uniformly distributed event, such as children cleaning their rooms, the formula (a + b) / 2 is used, giving an expected wait time of 8 days.
Step-by-step explanation:
The frequency of professional cleaning for ventilation hoods to reduce the risk of fires can vary depending on the volume of cooking and the type of cooking being done. In a commercial setting, for example, the National Fire Protection Association (NFPA) Standard 96 suggests that systems serving solid fuel cooking operations should be inspected monthly, those serving high-volume cooking operations such as 24-hour cooking, charbroiling, or wok cooking should be inspected quarterly, those serving moderate-volume cooking operations should be inspected semi-annually, and those serving low-volume cooking operations, such as churches, day camps, seasonal businesses, or senior centers should be inspected annually.
Always ventilate and follow manufacturers' instructions when using products or appliances that may release pollutants into the indoor air. As for residential settings, manufacturers' instructions should guide the maintenance schedule, but a general rule of thumb would be at least once per year for heavy use and potentially less for lighter use. This is a guideline, however, and the specific frequency should be determined by the amount of use and the type of cooking. In the mathematical problem related to the cleaning frequency of a child's room that is uniformly distributed between 1 to 15 days, the expectation can be calculated using the formula for the uniform distribution (a + b) / 2, where 'a' is the minimum value and 'b' is the maximum value. Here, a = 1 day and b = 15 days, so the expected time to wait for a room to be cleaned is (1 + 15) / 2 = 8 days.