A diver's tank contains helium at 924 psi, nitrogen at 1456 psi and oxygen. The total
pressure is 2803 psi. What partial pressure is
exerted by the oxygen?

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation: