Fluid Mechanics

A vessel contains oil (density $= 0.8 \text{ gm}/\text{cm}^3$) over mercury (density $= 13.6 \text{ gm}/\text{cm}^3$). A homogeneous sphere floats with half of its volume immersed in mercury and the other half in oil. The density of the material of the sphere in $\text{gm}/\text{cm}^3$ is