Short Riddles and Answers

Question: Some use me, while others do not.
Some remember, while others have forgot.
For profit and gain I'm used expertly, I can't be picked off the ground or tossed in the sea.
Only gained through patience and time, can you unravel my rhyme?

Question: there was a two storeyed building.one the second floor was standing a father.on the first floor was standing his son.and in the ground floor was standing a lady.what does the son say to father if he has to say a lady is standing down in one word.

Question: Jasmine has a toaster with two slots that toasts one side of each piece of bread at a time, and it takes one minute to do so.

If she wants to make 3 pieces of toast, what is the least amount of time she needs to toast them on both sides?

Question: A man walks into a completely dark room. There is a box on a table at the other end of the room and immediately the man knows one of the contents of the box. He cannot smell, see, or hear it.

How does he immediately know what is inside?

Question: A murderer is condemned to death. He has to choose between three rooms. The first is full of raging fires, the second is full of assassins with loaded guns, and the third is full of lions that haven't eaten in 3 years. Which room is safest for him?