Answer:
Ariel will be at an elevation of -3 meters.
Step-by-step explanation:
We have been given that Eric is swimming along the surface of the sea. He uses positive numbers to represent elevations above the surface of the sea and negative numbers to represent depths under the surface of the sea.
Since Eric is swimming along the surface of the sea, so his elevation will be 0.
As we are told that Mark is sitting above Eric and Eric uses positive number for elevation above surface of the sea, so Mark's elevation will be positive.
As we are told that Ariel is diving below Eric and Eric uses negative number for elevation below surface of the sea, so Ariel's elevation will be negative.
Therefore, Ariel will be at an elevation of -3 meters.