A closed system consisting of 4 lb of gas undergoes a process in which the relation between pressure and volume is pVn = constant. The process begins with p1 = 15 psi, v1 = 1.25 ft3/lb and ends with p2 = 53 psi and v2 = 0.5 ft3/lb. Determine: a) the volume in ft3 occupied by the gas at states 1 and 2, and b) the value of n.