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 ?

A. She visits M before Q.
B. She visits N before R.
C. She visits P before M.
D. She visits P before S.
E. She visits Q before R.
Answer: A . She visits M before Q.


Clearly, she visits M before N and N before Q. So, she must visit M before Q.