What month of the year has 28 days?

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

When can we add 2 to 11 and get 1 as the correct answer?

Can you complete the sequence?

192, 021, 222, 324, 252, 627, 2__, 9__?

A person is found murdered in his Chamber. When the crime scene is investigated, the Investigator find out that there is a calendar on which the victim has written a few numbers with his blood. The numbers are 4, 11, 11 and 4.

There are four suspects in the murder, John, Jacob, Anna and Lee. Can you find out who is the murderer?

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.

What goes through cities and fields, but never moves?

What is always in front of you but can’t be seen?

Prove that twice of ten is the same as twice of eleven.