The Concentration of Water Vapor in a Sample of Air

The concentration of water vapor in a sample of air that has a partial pressure of water of 0.91 torr and a total pressure of air of 735 torr is _ ppm.

A) 8.1 × 10^{- 4}
B) 0.12
C) 1.2 × 10³
D) 0.81
E) 1.2