In a row of $40$ students facing North, Kailash is $6^{th}$ to the left of Soman. If Soman is $30^{th}$ from the left end of the row, how far is Kailash from the right end of the row (in $^{th}$)?

Sanal's position in a row is $12^{th}$ from the front side and $47^{th}$ from the back side. How many persons are standing in that row?

Rahul ranked ninth from the top and thirty-eighth from the bottom in a class. How many students are there in the class?

How many even numbers are there in the following sequence of numbers which are immediately followed by an odd number as well as immediately preceded by an even number?
$8, 6, 7, 6, 8, 9, 3, 2, 7, 5, 3, 4, 2, 2, 3, 5, 5, 2, 2, 8, 1, 1, 9$

How many $7$'s are there in the following series which are not immediately followed by $3$ but immediately preceded by $8$?
$8, 9, 8, 7, 6, 2, 2, 6, 3, 2, 6, 9, 7, 3, 2, 8, 7, 2, 7, 7, 8, 7, 3, 7, 7, 9, 4$

In a queue of children,Kashish is fifth from the left and Mona is sixth from the right. When they interchange their places among themselves,Kashish becomes thirteenth from the left. Now what will be Mona's position from the right (in $^{th}$)?