Seven persons $P, Q, R, S, T, U$ and $V$ participate in and finish all the events of a series of swimming races. There are no ties at the finish of any of the events. $V$ always finishes somewhere ahead of $P$. $P$ always finishes somewhere ahead of $Q$. Either $R$ finishes first and $T$ finishes last or $S$ finishes first and $U$ or $Q$ finishes last. If in a particular race $V$ finished fifth,then which one of the following would be true?

$A$ training college has to conduct a refresher course for teachers of seven different subjects: Mechanics,Psychology,Philosophy,Sociology,Economics,Science,and Engineering from $22^{nd}$ July to $29^{th}$ July.
$1.$ The course should start with Psychology.
$2.$ $23^{rd}$ July,being Sunday,should be a holiday.
$3.$ Science subject should be on the previous day of the Engineering subject.
$4.$ The course should end with Mechanics.
$5.$ Philosophy should be immediately after the holiday.
$6.$ There should be a gap of one day between Economics and Engineering.
Which subject is followed by Science?

In a pile of $10$ books,there are $3$ History,$3$ Hindi,$2$ Mathematics,and $2$ English books. From the top,an English book is between a History and a Mathematics book,a History book is between a Mathematics and an English book,a Hindi book is between an English and a Mathematics book,a Mathematics book is between two Hindi books,and two Hindi books are between a Mathematics and a History book. Which subject book is at the $6^{th}$ position from the top?

$(i)$ Eight persons $E, F, G, H, I, J, K$ and $L$ are seated around a square table,two on each side.
$(ii)$ There are three lady members and they are not seated next to each other.
$(iii)$ $J$ is between $L$ and $F$.
$(iv)$ $G$ is between $I$ and $F$.
$(v)$ $H$,a lady member,is second to the left of $J$.
$(vi)$ $F$,a male member,is seated opposite $E$,a lady member.
$(vii)$ There is a lady member between $F$ and $I$.
Who among the following is to the immediate left of $F$?

There is a group of five persons $A, B, C, D$ and $E$. In the group,there are a Professor of Philosophy,a Professor of Psychology,and a Professor of Economics. $A$ and $D$ are ladies who have no specialization in any subject and are unmarried. No lady is a philosopher or an economist. There is a married couple in the group of which $E$ is the husband. $B$ is the brother of $C$ and is neither a psychologist nor an economist. Who is the Professor of Economics?

$(A)$ $P, Q, R, S$ and $T$ are sitting in a circle facing the centre.
$(B)$ $R$ is immediate left of $T.$
$(C)$ $P$ is between $S$ and $T.$
Who is to the immediate left of $R$?