What is black when you buy it, red when you use it, and gray when you throw it away?

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

What can jump higher than a building?

Which is the smallest number that you can write using all the vowels exactly once?

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?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

Prove that the below maths equation is true.

8 + 8 = 91

What building has the most stories?

It is a 5 letter word if you take away first letter it is something you get from sun, if you remove second letter you will get something to eat, if you remove third letter you get a word you use in pointing at and if you remove the fourth letter you get something to drink. What is it?

There was a man he lives in a hotel each morning he presses the first floor button each evening if there is a person in the elevator he asks him to press the 10 floor button if there is no one in the elevator he takes the stairs why.