Using Only Five 5's and any mathematical operator make sum as 37

You can see it everyday, But cannot touch it at will. What is it?

What 5-letter word typed in all capital letters can be read the same upside down?

Use the digits from 1 up to 9 and make 100.

Follow the rules.
=> Each digit should be used only once.
=> You can only use addition.
=> For making a number, two single digits can be combined (for example, 4 and 2 can be combined to form 42 or 24)
=> A fraction can also be made by combining the two single digits (for example, 4 and 2 can be combined to form 4/2 or 2/4)

Question: how can we do this?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

Can you place six matchsticks in a manner that each of the matchsticks is in touch with the other five matchsticks?

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

You need to complete the maze by entering from the entrance marked below in the figure near the yellow circle, bottom left and leaving from the exit point near the green circle, bottom middle.

Rule of Game: You can move only by exchanging green and yellow circles.

I inserted a coin in a bottle and closed its mouth with the help of a cork. Now, I was able to take the coin out from the bottle without taking out the cork or breaking the bottle. Can you tell me how I did it?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?