An axial flow pump is to discharge 5 cusecs at an operating speed of 1450 rev/min. The inner and outer diameters of the impeller are to be 5.5 in. and 11 in. respectively. If the head developed according to the vector triangles is 20 ft, determine the angle of the vane tips at the inner and outer diameters and the corresponding diffuser blade angle (the diffuser blades are the stationary blades after the impeller).