How can a man go eight days without sleep?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

I have teeth but i don't bite. Who Am I ?

Nodes are shown below and you need to connect them based on the following rule: Every node can be connected to the number of nodes inside them, i.e. the first node there is a value of 1 which indicates that the first node can connect to exactly one node only.Can you do it?

John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

In a football game, Christina defeated Teresa by 2 - 0 but no man from either side scored. How can this be possible?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

John has played 50 ODI's and his average is 50. How many runs should he score in his 51st ODI, so that his average score jumps to 51?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

What has a ring but no finger?