A king's crown has a volume of 110 cm cubed and a mass of 1800 g.?
Pure gold is very ductile. It can never be used in an ornament. It has to be used along with copper to give the ornament a rigid shape. So, no ornament can be of pure gold. In this case, the density of the crown is 1800/110 = 16.36 g/cc which is below the standard density of gold which is 19.3 g/cc. Hence the crown is not of pure gold.