If an appliance rated at 30,000 BTU/hr operates continuously, approximately how many hours per gallon will it last?

To determine how long a 30,000 BTU/hr appliance can operate on a gallon of propane, we need to know the energy content of propane. Propane typically contains about 91,500 BTUs per gallon.

To calculate the hours of operation, we divide the total BTUs in a gallon of propane by the BTU/hr rating of the appliance.

Using the formula:

Hours of operation = BTUs per gallon / BTU/hr rating

= 91,500 BTUs / 30,000 BTU/hr

= 3.05 hours

This means that a 30,000 BTU/hr appliance can operate for approximately 3 hours on one gallon of propane. Since the question asks for an approximate value, rounding this down leads to the answer of approximately 3 hours.

Therefore, the choice that reflects this calculation is the correct answer.