The air density at Mount Everest is less than that at the sea level. Mountaineers find that for one trip lasting a few hours, the extra oxygen needed by them corresponds to 30,000 cc at sea level (pressure 1 atmosphere, temperature 27∘C). Assuming that the temperature around Mount Everest is –73∘C and that the oxygen cylinder has a capacity of 5.2 litre, the pressure at which O2 be filled (at site) in the cylinder is