Which is the third number to the left of the number which is exactly in the middle of the following sequence of numbers?
$1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 4, 6, 8, 9, 7, 5, 3, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1$

How many $8$'s are there in the following number series which are exactly divisible by their immediately preceding and also divisible by their immediately succeeding numbers?
$8, 2, 4, 5, 1, 7, 2, 8, 4, 8, 4, 2, 2, 8, 2, 6, 9, 8, 4, 5, 4, 8, 3, 2, 8, 4, 3, 1, 8, 3$

In a row of girls, Rita and Monika occupy the ninth place from the right end and tenth place from the left end, respectively. If they interchange their places, then Rita and Monika occupy the eighteenth place from the left end. How many girls are there in the row?

Ram remembers that Lakshman's birthday is after $19^{th}$ but before $22^{nd}$ November,whereas Anil remembers that Lakshman's birthday is after $20^{th}$ but before $24^{th}$ November. Which day is Lakshman's birthday?

Sachin is sitting to the immediate left of Meena but not next to Bharti. Parveen is sitting to the right of Bharti. If the four friends are sitting in a circle,who is sitting to the immediate right of Meena?

Some boys are sitting in a row. $P$ is sitting fourteenth from the left and $Q$ is seventh from the right. If there are four boys between $P$ and $Q,$ how many boys are there in the row?