def calculate_time(cents_per_kWh, wattage, dollar_amount):
    """ Returns the time (in hours) that it would take to reach the monetary price (dollar_amount)
        given the cost of energy usage (cents_per_kWh) and power (wattage) of a device using that energy.
    """
    return 1 / (cents_per_kWh) * 1e5 * dollar_amount / wattage