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

A man lives on the fifteenth floor of an apartment building. Every morning he takes the elevator down to the lobby and leaves the building. In the evening, he gets into the elevator, and, if there is someone else in the elevator, or if it was raining that day, he goes back to his floor directly. Otherwise, he goes to the tenth floor and walks up five flights of stairs to his apartment. Can you explain why he does this?

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

A cat had three kittens: Snophy, Topsy and Jorden. What was the mother's name?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

Can you find the 09 errors in the picture below?

What is harder to catch the faster you run?