Use the direct-design method to compute the moments for the column-strip and middle-strip spanning perpendicular to the edge of the exterior bay of the flat-plate slab shown in Fig. P13-3. Assume the slab is 7½ in. thick and supports a superimposed dead load of 25 psf and a live load of 50 psf. There is no edge beam. The columns are all 18 in. square.