What is the first step in calculating the total energy cost for the lamps?

The correct initial step in calculating the total energy cost for the lamps involves multiplying the number of lamps by their wattage. This step is important because it gives you the total wattage used by all the lamps combined, which is essential for determining the energy consumption.

When you know the total wattage, you can then use that figure to find out how much energy is consumed over a given period and subsequently calculate the cost. This forms the basis of energy calculations, as energy use in kilowatt-hours (kWh) is influenced directly by both the total wattage and the duration of usage.

By focusing on the total wattage from the beginning, you set the stage for accurate calculations in subsequent steps, such as determining the hours in use and applying cost rates based on your utility.