Why is the Hole below a Lock?

What is the relationship between these matchstick pictures below?

What kind of band never plays music?

Can you tell a 3D object that has just two surfaces?

Before Mount Everest was discovered, what was the highest mountain in the world?

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?

You are on a Boat in the mid of a river. You have two cigarettes with you. One of these two you have to light, how will you light the cigarette?

A quarter is one-fourth of a dollar but Mr. John has changed the equation as below :

DOLLAR * 4 = QUARTER

Can you replace each letter with a digit to make the above solution correct?

A cat had three kittens: Snophy, Topsy and Jorden. What was the mother's name?

If we change the South-East direction into North and North-East into West and all others similarly.
Can you find out which direction will be in the place of South-West direction?