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?

When is the top of a mountain similar to a savings account?

Remove two matchsticks to make the below equation correct.

Count the number of triangles in the given picture.

How many triangles are there in the picture below?

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 are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

The pound is not a finish.

We are sharing a few instructions below, which you have to use in any suitable order to modify the above sentence such that the end sentence is a scientific fact.

- Eliminate a letter and supplement another in its place.
- Take away one word.
- Remove one letter from one word.
- Get rid of two letters from one word.
- Swap a word with its antonym.

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?