Solution:

As marked O(letter 'O') is written instead of 0(number zero)

Solution:

At every floor, the detective had to open the window himself. If the man had committed suicide, then at least one of the windows must have been open. A person who is committing suicide won’t close the window behind him. Thus he knows that someone pushed him off the edge and closed the window afterwards.

Solution:

Either your read from start or from ends, it will be same

Solution:

This puzzle has no answer if you are considering this figure in a 2d domain. However if you follow it on a three-dimensional plane, you can do it like shown in the figure given.

Solution:

NONE, holes are empty.

Solution:

A
D
C
A
B

Solution:

The man asked the king that he wanted to die of old age.

Solution:

We now have a square of 3x3 size, 2 squares of 2x2 size and 5 squares of 1x1 size.

Solution:

The Bangladeshi seaman is the thief. This is because the Japanese flag cannot be identified as upside down as it is the same both ways. Thus he is just trying to escape the situation.

Solution:

The clerk said that every day the password is CHANGED. Changed is the password.

Solution:

The brain teaser can be solved as shown in the image below.