What can go up a chimney down, but can’t go down a chimney up?

What goes up but never comes down?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

There are two dice with empty faces in front of you and a marker. You can mark any number on each of the faces of the two dice, but you have to display all 31 days of the month using the two of them.

Which numbers will you mark on which dice so that you can easily depict all the dates of the month?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room?

I am written with two letters.
I said with the one.
I usually am seen with the two.

Who am I?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

What does below rebus means ?

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?