Our laboratory plans to use one, 10-liter tank of refrigerant 134a every week. So off you go to check the cost of fill-ups at the two possible suppliers. At Chem Mart, the filled tank is returned to you at 10 bar and 90 C for $10.00. At Super Discount Chemicals, they also wanted to charge you $10.00 for the fill up. You protested that the charge should be only $6.00 since they only gave you 6 bar at 0 C. You bargained and they eventually lowered the price to $8.00. You are not happy about this but decide to be scientific about the whole thing and calculate the cost/kg charged by these two suppliers. Who should you buy from?