In 1983, the United States began coining the cent piece out of copper-clad zinc rather than pure

Question:

In 1983, the United States began coining the cent piece out of copper-clad zinc rather than pure copper. The mass of the old copper penny is 3.083 g, while that of the new cent is 2.517 g. Calculate the percentage of zinc (by volume) in the new cent. The density of copper is 8.960 g/cm3 and that of zinc is 7.133 g/cm3. The new and old coins have the same volume.