Sitting in a row in front of a camera,$Mr. X$ is on the left of the person sitting in the centre but is on the right of $Mr. Y$. $Mr. P$ is on the right of $Mr. Z$ and $Mr. R$ is on the right of $Mr. P$. $Mr. R$ is the second person from the person sitting in the centre. Who is the person sitting in the centre?

The sum of the incomes of $A$ and $B$ is more than that of $C$ and $D$ taken together. The sum of incomes of $A$ and $C$ is the same as that of $B$ and $D$ taken together. Moreover,$A$ earns half as much as the sum of the incomes of $B$ and $D$. Whose income is the highest?

Four young men Raj,Prem,Ved,and Ashok are friendly with four girls Sushma,Kusum,Vimla,and Poonam. Sushma and Vimla are friends. Ved's girlfriend does not like Sushma and Vimla. Kusum does not care for Ved. Prem's girlfriend is friendly with Sushma. Sushma does not like Raj. Who does not like Sushma and Vimla?

Six persons $A, B, C, D, E$ and $F$ are sitting in two rows,three in each. $E$ is not at the end of any row.
$D$ is second to the left of $F$.
$C$,the neighbor of $E$,is sitting diagonally opposite to $D$.
$B$ is the neighbor of $F$.
Which of the following are sitting diagonally opposite to each other?

$(i)$ There are seven books,one each on Psychology,Hindi,English,Sociology,Economics,Education,and Accountancy,lying on a table one above the other.
$(ii)$ Sociology is on the top of all the books.
$(iii)$ Accountancy is immediately below Education,which is immediately below Sociology.
$(iv)$ Economics is immediately above Psychology,but not in the middle.
$(v)$ Hindi is immediately below Psychology.
If Sociology and English,Accountancy and Hindi,and Education and Psychology interchange their positions,which book will be between Psychology and Sociology?

$A, B, C, D, E$ and $F$,not necessarily in that order,are sitting on six chairs regularly placed around a round table. It is observed that:
$1$. $A$ is between $D$ and $F$.
$2$. $C$ is opposite $D$.
$3$. $D$ and $E$ are not on neighbouring chairs.
Which of the following pairs must be sitting on neighbouring chairs?