Question

If the absolute pressure of a gas is 550.280 kPa, its gage pressure is

A. 101.325 KPa
B. 277.280 KPa
C. 448.955 KPa

Answer 1

Here is a good discussio of different types of pressure gauges. Absolute pressure = gauge pressure plus atmospheric pressure.
http://en.wikipedia.org/wiki/Pressure_measurement