$A, B, C, D, E$ and $F$,not necessarily in that order,are sitting on six chairs regularly placed around a round table. It is observed that:
$A$ is between $D$ and $F$.
$C$ is opposite to $D$.
$D$ and $E$ are not on neighbouring chairs.
Which one of the following pairs must be sitting on neighbouring chairs?

In a group of $5$ persons $A, B, C, D,$ and $E,$ there is a professor,a businessman,and an artist. $A$ and $D$ are ladies who are unmarried and do not work. Of the married couple in the group,$E$ is the husband. $B$ is the brother of $A$ and is neither a businessman nor an artist. $E$'s wife is an artist. Who is the artist?

In an examination,Raj got more marks than Mukesh but not as many as Priya. Priya got more marks than Gaurav and Kavita. Gaurav got less marks than Mukesh but his marks are not the lowest in the group. Who is second in the descending order of marks?

In a car exhibition,seven cars of seven different companies viz. Cardilac,Ambassador,Fiat,Maruti,Mercedes,Bedford,and Fargo were displayed in a row,facing east such that:
$(1)$ Cardilac car was to the immediate right of Fargo.
$(2)$ Fargo was fourth to the right of Fiat.
$(3)$ Maruti car was between Ambassador and Bedford.
$(4)$ Fiat,which was third to the left of Ambassador car,was at one of the ends.
Which of the following was the correct position of the Mercedes?

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 wife of $E$?

$A$ truck,a car,and a motorcycle have equal kinetic energies. If equal stopping forces are applied and they stop after traveling a distance of $X$,$Y$,and $Z$ respectively,then: