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?

There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.

If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.

Will you accept that bet?

How many letters are in the alphabet?

Which word is least like the others? Third, fourth, fifth, sixth, seventh, eighth, ninth?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

If a wheel has 54 spokes, how many spaces are there between the spokes?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

Can you identify the direction in which this bus is moving; left or right?

Hint: The bus is moving on the roads of London.

Solve the equation in the image by looking at the pattern closely.

Buy me, smell me or deliver me, I do not change.

Who am I?