What has to be broken before you can use it?

What has many keys but can’t open a single lock?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

You enter your friend's room. He is not in his room. Although you see that on the bed there are two dogs, five cats, two giraffes and three pigs. Also, a couple of chickens and ducks are flying in the room.

Calculate the number of legs standing on the floor.

I don't get anymore wetter, no matter how much rain falls on me.

What demands an answer, but asks no questions

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.