hi hello! how to solve this using EXCEL SOLVER

wiht Y as a binary variable (0,1)

A large drug company must determine how many sales representatives to assign to each of four sales districts. The cost of having n representatives in a district is ($88,000 + $80,000n) per year. If a rep is based in a given district, the time it takes to complete a call on a doctor is given in Table 48 (times are in hours). Each sales rep can work up to 160 hours per month. Each month the number of calls given in Table 49 must be made in each district. A fractional number of representatives in a district is not permissible. Determine how many representatives should be assigned to each district. TABLE 48 Actual Sales Call District Rep's Base District 1 2 3 4 4 1 2 1 1 4 5 7 5 3 1 2 7 5 2 3 3 5 4 1 TABLE 49 District Number of Calls 1 2 50 80 100 60 3 4