During which month do people sleep the least?

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?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

What breaks yet never falls, and what falls yet never breaks?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

What jumps when it walks and sits when it stands?

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

What you cannot hold but it is yours?