What is always in front of you but can’t be seen?

Every words stands for unique digit that makes the arithmetic equation true

SEVEN + SEVEN + SIX = TWENTY.

What are the digits ?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

I travel all around the world but always stay in the corner. What am I?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

A man wants to cross the pit of fire which is 25 feet in length and he has 2 planks(fire resistant) 19 feet in length. How can he cross the pit of fire alive?