An intensive property of a substance is independent of the amount present why

This is because the density of an object is independent from it's mass. Example is a gram of marbles and a kilogram of marbles still have the same density, as long as the temperature and the pressure are equal. So no matter how many of one type of thing as long as the variables for each are the same, the density will never change. The intensive property suggests that the density is different from it's mass, like I just explained.