What is more dense 1000 ml of water or 1000 ml of water with C g of salt added?

1000 ml of pure water has a density of 1 g/ml, resulting in a mass of 1000 grams. When C grams of salt is added, the total mass increases to 1000 + C grams while the volume remains approximately the same at 1000 ml. Therefore, the density of the water with salt is greater than that of pure water, as density is mass divided by volume, leading to a higher density due to the increased mass.