What has to be broken before you can use it?

What demands an answer, but asks no questions

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

What does this rebus picture identify?

What does this rebus means ?

What has no start, end, or centre?

Your last good ping-pong ball fell into a narrow metal pipe embedded one foot deep in concrete.
How can you get it out undamaged, if all the tools you have are your tennis paddle, shoe laces, and plastic water bottle, which does not fit into the pipe?

What type of tree can I carry in my hand?