Can you find out the missing number in the grid?

If we tell you that there is a relation between the numbers and letters in the given figure, can you analyze it and find the missing letter in the last box?

Why do we preferably have round manhole covers and not square ones?

How can you make a TV, a bed, a dog, and a car liquid?

what does the below rebus mean?

On a special event at the prison, 5 prisoners John, Jacob, Krist, Tang, and Dang given a chance to go to a sauna and can bring one thing with them.

Following are the things that the prisoners bring with them.
John: A soda
Jacob: Thermos
Krist: Book named "How to kill"
Tang: A Walkman
Dang: Harmonica

Since it is a Sauna, no one can see each other. After a while When the steam is switched, Tang was found dead and there was blood all around.
J Bond was called and he instantly come to know who can be the murderer. How?

Can you count the number of squares in the figure below?

Find the next number in the following series:
6, 14, 26, 98, __?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den