Fill up the blanks:
Problem 1. In a problem involving capital budgeting applications, the 0-1 variables designate the __________ or _________ of the different projects.
Problem 2. If exactly one investment is to be selected from a set of five investment options, then the constraint is often called a ________ constraint.
Problem 3. If we are solving a 0-1 integer programming problem, the constraint x1 + x2 <= (less than equal to) 1 is a _________ constraint.
Problem 4. If we are solving a 0-1 integer programming problem, the constraint x1 <= (less than equal to) x2 is a _________ constraint.
Problem 5. If we are solving a 0-1 integer programming problem, the constraint x1 = x2 is a ____________ constraint.