If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

What came first, the chicken or the egg?

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?

Which tank will fill first?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

In the image given, you can find several triangles. Can you count them all?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?