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

What do you think with the 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?

Name a key which is hardest to turn.

We know that the number 7 is the prime followed by a cube. Which next number is also a prime followed by a cube?

Why do we preferably have round manhole covers and not square ones?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

You have a square. What you have to do is cut and reassemble the square such that you create a Red Cross sign that has the same volume as that of the square.

If 1+9+8=1, what is 2+8+9?

Why is the Hole below a Lock?