We need to visit 6 cities by using as minimum number of vehicles as possible. We identify 10 feasible paths as follows: We have the following data: U = {1,2,3,4,5,6,7,8,9,10} S1= {5,6} S2 = {3,5,6} S3 = {1,4} S4= {2,3,4,6} S5 = {1,2} S6 = {2,6} S7= {5} S8 = {3,4,6} S9 = {3,5} S10 = {4} Transportation costs are as follow: S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 C =[18, 22,14, 36, 17, 14, 8, 24, 14, 71 ] By assuming that each path can be visited once only: a. Formulate the problem according to set partitioning problem! b. determine how many vehicles is needed at the transportation costs of the solution!