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

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

Solve the following series:
AZ, GT, MN, __, YB

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?

What is the end of everything?

A wealthy man lives alone in a small cottage. Being partially handicapped he had everything delivered to his cottage. The mailman was delivering a letter one Thursday when he noticed that the front door was ajar. Through the opening he could see the man's body lying in a pool of dried blood. When a police officer arrived he surveyed the scene. On the porch were two bottles of warm milk, Monday's newspaper, a catalog, flyers, and unopened mail. The police officer suspects it was foul play. Who does he suspect and why?

You can see three almost identical images below. Can you spot the odd one out from them?