A five-colour paint blending operation purchases paint. These are the three primary colours of red, blue, and yellow as well as white and black. The supplier has five vats available for receiving these colours; the white and black vats each have a capacity of 5000 litres. The capacity of each main colour vat is 25,000 litres. No matter what colour, all paint must be purchased for $9 per litre. Each product is produced using a specific proportion of the five fundamental paints. This is a list of what they sell: