Shanta runs an industry in a shed that was in the shape of a cuboid surmounted by half-cylinder. If the base of the shed is 7 m×15 m and height of the cuboidal portion is 8 m, find the volume of the air that the shed can hold. If the industry requires machinery which would occupy a total space of 300 m^3 , and there are 20 workers each of whom would occupy 0.08 m^3 space on an average, how much air would be in the shed when it is working. (Take π = 7/22)