10^7 is the correct answer
1. Gold has a higher density than silver. This is shown by the equation D = M/V, where D is density, M is mass, and V is volume. This means that when the jeweler put an equal amount of mass in, he had
to put a greater volume of silver to equal the same mass of gold. The total volume of the crown increased.
2. Archimedes discovered that the amount of volume he put in (whether his body, or the crown) would be equal to the rise in volume of the water level (that is, the new water level versus the old one before anything had been put in). Archimedes would have then gotten a block of gold that weighed the same as the crown and checked the volume rise. Then once he tested the crown, he would have seen that the volume rise was higher than expected, and he would know that the jeweler had included some silver.
I think its B not sure tho sorry
We need a better picture, we can't even tell which is #7