A scuba driver is positioned at - 30feet how many feet will she have to rise to change her postion to z12 feet

On a graph, the x and y axes are used for 2 dimensions. A scuba diver can stay at 30 feet below sea level and move forward, backwards, left, and right which would be 2 dimensions, however swimming up toward the surface would be the 3rd dimension (z axis). So to answer the question, 12 - (-30) = 42 feet.