dolution

In assessing project managers, a CEO states:“What counts for me are com- pleted projects and the amount of overtime worked. With two project managers, I find the manager who finishes at least as many projects at least as good as the other manager. If both complete the same number of projects, I find the manager who puts in at least as much overtime, at least as good as the other manager.”
Are the CEO’s preferences rational?
Show graphically, why the CEO’s preferences cannot be characterized by a value function. (Hint: A project manager can be characterized in two-dimensional space by the number of completed projects and the hours of overtime.)