Continuous-time separated linear programming problems have a wide range of real-world applications such as in business, economics, finances, communications, manufacturing, and so on. In this paper, we extend the technique that is presented by Wen et al. [1] for two classes of these problems. We introduce both primal and dual models for separated problems. In addition, by using discrete problems we obtain approximate solutions with error bounds. Moreover, we establish a computational procedure, to solve any separated continuous-time model and any state-constrained separated model. Furthermore, after we put the separated problem in the form that is presented by Wen et al. [1], we conclude that approximate solutions converge to an optimal solution for continuous-time separated problems.