There are three schools districts in the town of Bushville. the number of black and white students in each district are shown in Table 70. The supreme Court requires the schools in Bushville to be racially balanced. Thus, each school must have exactly 300 students, and each schools must have the same number of black students. The distances between the districts are shown in Table 70. Formulate a balanced transportation problem that can be used to determine the minimum total distance that students must be bused while still satisfying the Supreme Court's requierements. Assume that a student who remains in his or her own district will not be bused.

TABLE 70 No. of Students District Whites Blacks 210 120 210 30 180 150 Distance to (Miles) District 3 District 2 TABLE 70 No. of Students District Whites Blacks 210 120 210 30 180 150 Distance to (Miles) District 3 District 2