In a class of $40$ students,Samir's rank from the top is $12^{th}$. Alok is $8$ ranks below Samir. What is Alok's rank from the bottom?

If the position of the first and the sixth digits of the sequence of numbers $8, 9, 0, 3, 2, 1, 4, 6, 7, 5$ are interchanged,the second and the seventh and so on,which number would be seventh from the right end?

How many days will there be from $26^{th}$ January,$1988$ to $15^{th}$ May,$1988$ (both days included)?

In a row of trees,one tree is fifth from either end of the row. How many trees are there in the row?

In a queue,Amrita is $10^{th}$ from the front while Mukul is $25^{th}$ from behind and Mamta is just in the middle of the two. If there are $50$ persons in the queue,what position does Mamta occupy from the front (in $^{th}$)?

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