A 10-stage axial-flow compressor of 50% reaction design has a mean blade velocity of 250 m/s and the blade inlet angle for each row is 45°. The ratio of flow velocity to blade velocity is 0.75 , the work done factor for each stage is 0.87 and the isentropic efficiency of the compressor is 0.85 . Assuming an air inlet temperature of 20°C. Calculate the exit angle of the blades