An ice cube is floating in water above which a layer of lighter oil is poured. As the ice melts, interface and the uppermost level of oil will respectively

The question seems to be incomplete. However, I can provide an answer based on the information given.

When an ice cube melts in water, it doesn't cause the water level to rise. This is because the volume of water that the ice displaces while it is floating is the same as the volume of water it adds when it melts. This is due to Archimedes' principle, which states that the buoyant force (the force that supports the ice cube) is equal to the weight of the fluid displaced.

As for the oil layer above the water, it is lighter than water and will remain on top. The level of the oil will not be affected by the melting of the ice cube because the ice is not displacing any oil (it's displacing water).

So, the interface (the boundary between the water and the oil) will remain at the same level and the uppermost level of the oil will also remain the same as the ice melts.