8. Vertices b, c, d have supplies 30, 20, 10, respectively, and vertices j, k have demands of 30 and 25 in this network. 30 D 40 e 20 20 g on 15 j I 30 10/ 10 10 15 10 20 10 h 10 10 d 10 5 15 10 A f 20 20 15 20 20 k 25 (a) Find a flow satisfying the demands, if possible. (b) Reverse the direction of edge (h, g) and repeat part (a).