Operations research question?

Binary variable Xj = 1 if antenna j is active, 0 otherwise, where j takes values 1, 2, 3, 4 for the 4 antenas at the earth stations.


Also variable Y takes values 1 if an attendant is assigned to duty for monitoring, 0 otherwise.


a) Formulate the constraint that we need to add into the model to ensure that no more than three antennas can be active simultaneously


b) How would you formulate the constraint that ensures that the attendant is assigned to duty only if at least one or more antennas are active. If not, he is not assigned to duty.|||Ok, I'm not exactly sure what this is for but I'll take a shot at it:





a) 鈭?{j=1 to 4} Xj %26lt;= 3





b) Y = 1 if 鈭?{j=1 to 4} Xj %26gt; 0 and 0 otherwise.