Gold is alloyed with other metals to increase its hardness in making jewelry. Consider a piece of gold jewelry that weighs 9.85 g and has a volume of 0.675cm^3. The jewelry contains only gold and silver, which have densities of 19.3g/cm^3 and 10.5 g/cm^3, respectively. Assuming that the total volume of the jewelry is the sum of the volumes of the gold and silver that it contains, calculate the percentage (by mass) of gold in the jewelry.

It's a question for my AP Chem class. I feel like there's not enough info, but maybe not.
Thanks for your help.