At an Electronic Data Processing Unit, five out of the eight program sets P, Q, R, S, T, U, V and W are to be operated daily. On any one day, except for the first day of a month, only three of the program sets must be the ones that were operated on the previous day. The program operating must also satisfy the following conditions :
(i). If program P is to be operated on a day, V cannot be operated on that day.
(ii). If Q is to be operated on a day, T must be one of the programs to be operated after Q.
(iii). If R is to be operated on a day, V must be one of the programs to be operated after R.
(iv). The last program to be operated on any day must be either S or U.
Which of the following is true of any day's valid program set operation ?
Clearly, if R is operated at the fourth place, V must be operated somewhere after it. This is not possible since the fifth program is the last one which has to be either S or U. So, R cannot be operated at the fourth Place.