What has no start, end, or centre?

The LCD device should be able to tell the right time in the format HH:MM: SS in a 12-hour format. You can refer to the picture to get an idea. The device is a simple "level indicator" which has to be converted into a watch. How will you program it to work?

The centre of the third figure is empty. What digit should fit inside?

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?

Take away the whole and some still remain. What is it?

Remove two matchsticks to make the below equation correct.

What is the fastest way to double your money?

Prove that twice of ten is the same as twice of eleven.

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

Two men are in a desert. They both have packs on. One of the guys is dead. The guy alive has his pack open, and the guy who is dead has his pack closed. What is in the pack?