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?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

What does the below image rebus riddle means ?

What demands an answer, but asks no questions

Vin Diesel is pulling a theft and has planned to run away with all the cash kept in the safe. But the only way to open the safe is the 13 character password. He has a set of five clues given to him by a trustworthy source.

Exactly two of the below statements are false.
The password is contained within this sentence.
The password is not in this hint.
The password is within only one of these statements.
At least one of the above statements is a lie.

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

There are three light switches outside a room. One of the switches is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.

You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)

Your task is to then determine which switch controls the bulb?

What is the next number in this matchsticks series riddle?