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

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

Can you find the missing piece of the Porsche?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Can you write down eight eights so that they add up to one thousand?

John was going on a jungle trip. He asked his wife to pack something to eat, something to drink and something to burn if he feels cold in the jungle. When John opens the backpack he found just one thing in the bag. What was it?

John was piloting a plane behind a car but was never able to overtake it. Why?

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?

If eleven plus two equals one, what does nine plus five equal?

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