Five tasks P, Q, R, S, and T need to be completed. Task P must be completed before Q, and R must be completed before S. Task T can be done at any time. What is a possible sequence of completing the tasks?
In a race, five participants A, B, C, D, and E finish in the following order: A finishes before C but after B. D finishes before E but after A. What is the order of finishers?