Can you count the number of triangles in the given figure?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

Can you fill the blank with the correct number?

6 30 870 756030 _____

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

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

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

What runs around the whole yard without moving?

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?