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?

Once upon a time, there was a castle on a square island. The entire island was surrounded by a 14m wide trench. The Romans had wanted to invade the castle and had brought a few wooden planks along with them to facilitate themselves in crossing the moat. The planks were however found to be only 13m long.

The Romans still managed to cross the trench. How did they do it?

In one of the popular batman series movie "Batman Forever", there was a riddle that goes like "Tear me off and then scratch my head and I was red then and now I am back. Who am I?

A donkey is behind another donkey
I'm behind that second donkey
But there is a whole nation behind me

It is a murder you can describe in a word.

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

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?

Which city is three-fifths chick two third cat and 50% goat?

What has 88 keys?

How far can you walk into the woods?

What four weights can be used to balance from 1 to 30 pounds?