What does below pictogram mean?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

What number when divided in half becomes zero?

No matter how little or how much you use me, you change me every month. What am I?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

There is a brick of gold and a brick of iron in a boat (both 10-inch blocks), if they are both dropped into the water which will make the water level higher?

A mathematician couple was having a Frappuccino in Starbucks sitting opposite to each other. Suddenly the guy noticed the text written on the paper in front of them and exclaimed that it was wrong. The girl denied it and said it is appropriate. Both are correct. What is written on the paper?

A tourist visits a small town for his research. While in the town, he decides to get a haircut. Since the town is quite small, there are only two barbers in the town � one on the North Street and one on the South Street. The barbershop on the North Street is a mess and the barber has a weird and pathetic haircut. While the barbershop at the South Street is pretty tidy and the barber as well has an impressive haircut.

Which barbershop will the tourist visit for his haircut and why?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?