Find the missing letter in the last circle logically in the given below picture.

I am the fastest animal but cannot climb the tree. What am I?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

Different lights make me strange by changing me into different sizes. What am I?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

What does the below image rebus riddle means ?

There are nine dots in the picture that has been attached with this question. Can you join all the dots by drawing four straight lines without picking up your pen?