Coal from source a produces sulfur at a rate of 15g per 100kg of coal. Coal from source b produces sulfur at a rate of 50g per 400kg of coal. Source a sells for $0.50 per kilogram and source b costs $1.25 per kilogram. a) How many grams of sulfur would be released from the combustion of $100 of each source of coal?
b) We use about 7 billion metric tons of coal worldwide per year for electricity generation. Using the least polluting coal source, how many kilograms of sulfur would be released per year?