What is the next number in this matchsticks series riddle?

Our product and our sum always give the same answer. Who are we?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

What number do you get when you multiply all of the numbers on a telephone's number pad?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

An office is divided into 8 cubicles. How many of the cubicles are painted if only 1/8 of the cubicles are painted?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

If Japan and Panama decided to merge into a single country, probably people will name it Japanama.

Can you think of two more such country's unions that could produce similar names like Japanama by overlapping their three letters?