2. A golden-colored cube is handed to you. The person wants you to buy it for $100, saying that it's a gold nugget. You pull out your old geology text and
look up gold in the mineral table, and read that its density is 19.3 g/cm3. You
measure the cube and find that it is 2 cm on each side, and has a mass of 40g.
What is its density? Is it gold? Should you buy it?