Count the squares in the matchstick puzzle below?

There is a shop where written:
Buy 1 for $1
10 for $2
100 for $3
I needed 999 and still only paid $3. How could this be financially viable for the shop-keeper?

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?

what's the probability of getting a king or a queen from a pack of 52 cards?

As shown in the image, the nine Dogs are square fenced. By constructing just two square fences can you make sure that two Dogs cannot meet each other without crossing the fence?

There are nine dots in the picture that has been attached with this question. Can you join all the dots by drawing four straight lines without picking up your pen?

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

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?