Decode this picture on T-Shirt and tell what it says ?

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?

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

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?

What came first, the chicken or the egg?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?

If,

Akriti = 631
Levis = 521
Sroti = 521
Aneel = 533
Then,
Sunil =?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?