Discussion

Answer: D

Now it is told that, there is no person to the left of A and P is sitting second to the right of A.

⇒ 1st position is occupied by the boy that is A and 3rd position is occupied by P that is girl.

From information (2), D is sitting at 8th position and he is a boy.

From information (1), C is sitting at 6th position and 5th and 7th position can be occupied by either R or S.

Therefore, our arrangement will look like

Now one of the positions from 2 and 4 will be occupied by boy and second one will be occupied by the girl.

From Information (3), B is a boy and he is sitting between two girls ie. at 4th position.

From information (4), Q is a girl and should be sitting at 2nd position.

Now our arrangement will look like

From above explanation, it is clear that number of boys between Q and R can be either 1 or 2.