It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

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 has many keys but can’t open a single lock?

Different lights make me strange by changing me into different sizes. What am I?

Can you write down eight eights so that they add up to one thousand?

What is wrong in the below Picture?

Steffi's daughter Jazelle needs to be picked up from school every day.
Steffi asks one of her colleagues to pick up Jazelle from the school. Steffi devised a password system to confirm that Jazelle goes with the correct colleague only.

The password on Monday was SJM16.
The password on Wednesday was TAW39.

What will the password be for Friday?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

I have Rs.50 and I spend it in the way as below.

When I asked a girl's name she told me her name is the date '07/09/2001'.

I thought for a few seconds and then I got her name. Do you?