There are six cities $A, B, C, D, E$ and $F$. $A$ is not a hill station. $B$ and $E$ are not historical places. $D$ is not an industrial city. $A$ and $D$ are not historical cities. $A$ and $B$ are not alike. Which two cities are industrial centres?

$A, B, C, D, E$ and $F$ are seated in a circle facing the centre. $D$ is between $F$ and $B$. $A$ is second to the left of $D$ and second to the right of $E$. Who is facing $A$?

There are six cities $A, B, C, D, E$ and $F$. $A$ is not a hill station. $B$ and $E$ are not historical places. $D$ is not an industrial city. $A$ and $D$ are not historical cities. $A$ and $B$ are not alike. Which two cities are neither historical places nor industrial centres?

$(i)$ 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.
Out of the following,which three books are kept above English book? To answer this question,which of the other informations,if any,is required?

Compare the knowledge of persons $X, Y, Z, A, B$ and $C$ in relation to each other.
$X$ knows more than $A$.
$Y$ knows as much as $B$.
$Z$ knows less than $C$.
$A$ knows more than $Y$.
The best knowledgeable person amongst all is:

Six persons $A, B, C, D, E,$ and $F$ are standing in a circle. $B$ is between $D$ and $C$. $A$ is between $E$ and $C$. $F$ is to the right of $D$. Who is between $A$ and $F$?