What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

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?

It can be easily calculated that the digits 0 to 9 can be arranged into 3628800 distinct ten-digit numbers.

But do you know how many of these numbers are prime?

What brings you down but never up?

What type of tree can I carry in my hand?

I can be cracked, made, told, and played. What am I?

A man fell off a smuggling boat into deep water. He could not swim and he was not wearing anything to keep him afloat. It took 30 minutes for the people on the boat to realize someone was missing. The missing man was rescued two hours later on the return trip. Why didn't he drown? Note:- He didn't know swimming, the sea was deep, and He wasn't holding anything

Bopanna was working on a murder case when he received a message about the location of the murder weapon.
The message was encrypted as below.

"deb mitciv eht edisni neddih si nopaew redrum ehT"

Tell me the location of the murder weapon.

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?