Air enters a diffuser with an averaged velocity of 360 m/s at a stagnation pressure and temperature of 340 kpa and 420 k and leaves at a stagnation pressure of 300 kpa with an averaged velocity of 120 m/s and a static pressure of 285 kpa. determine, (i) the static pressure and mach number of the air at inlet; (ii) the diffuser efficiency; (iii)the mach number at exit and the overall entropy increase.