A sales representative plans to visit each of six companies M, N, P, Q, R and S exactly once during the course of one day. She is setting up her schedule for the day according to the following conditions : (i). She must visit M before N and R. (ii). She must visit N before Q. (iii). The third company she visits must be P.
Which of the following must be true of the sales representative's schedule ?
Answer: A. She visits M before Q.
Clearly, she visits M before N and N before Q. So, she must visit M before Q.