A school district has I neighbourhoods, J schools and G grades at every school. Every school j has a capacity of C_{jg }for grade g. In every neighbourhood i, the student population of grade g is P_{ig}. The distance of school j from neighbourhood i is d_{ij} . We wish to assign all studentsto schools, whereas minimizing the total distance travelled by each students. Formulate an LP for this problem. (You may ignore the fact that the numbers of students must be integer.)