$A, B, C, D, E$ 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?

$1.$ There are five friends: Sonal,Ratheesh,Manoj,Ashok,and Gireesh.
$2.$ Sonal is shorter than Ratheesh but taller than Gireesh.
$3.$ Manoj is the tallest.
$4.$ Ashok is a little shorter than Ratheesh and a little taller than Sonal.
If they stand in the order of their heights,who will be in the middle?

$(i)$ $A, B, C, D, E, F$ and $G$ are sitting on a wall and all of them are facing east.
$(ii)$ $C$ is on the immediate right of $D$.
$(iii)$ $B$ is at an extreme end and has $E$ as his neighbour.
$(iv)$ $G$ is between $E$ and $F$.
$(v)$ $D$ is sitting third from the south end.
Name the person who should change places with $C$ such that he gets the third place from the north end.

There are five friends $-$ Sachin,Kunal,Mohit,Anuj,and Rohan.
Sachin is shorter than Kunal but taller than Rohan.
Mohit is the tallest.
Anuj is a little shorter than Kunal and a little taller than Sachin.
If they stand in the order of increasing heights,who will be the second?

Examine the following relationships among members of a family of $6$ persons $A, B, C, D, E,$ and $F$.
$1.$ The number of males equals that of females.
$2.$ $A$ and $E$ are sons of $F$.
$3.$ $D$ is the mother of two,one boy and one girl.
$4.$ $B$ is the son of $A$.
$5.$ There is only one married couple in the family at present.
Which one of the following inferences can be drawn from the above?

$(i)$ Seven books are placed one above the other in a particular way.
$(ii)$ History book is placed exactly above Civics book.
$(iii)$ Geography book is fourth from the bottom and English book is fifth from the top.
$(iv)$ There are two books in between Civics and Economics books.
How many books are there between Civics and Science books? To answer this question,which other extra information is required,if any,from the following?