Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

If we tell you that there is a relation between the numbers and letters in the given figure, can you analyze it and find the missing letter in the last box?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

James ordered a fishing rod, priced at $3.56. Unfortunately, James is an Eskimo who lives in a very remote part of Greenland and the import rules forbid any package longer than 4 feet to be imported. The fishing rod was 4 feet and 1 inch, just a little too long, so how can the fishing rod be mailed to James without breaking the rules? Ideally James would like the fishing rod to arrive in one piece!

There were three women in all the swimming costumes!
One was happy and the other two were sad!
The happy one was crying and the sad ones were smiling.
Why was this?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

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

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?

How can you drop a raw egg from a height onto a concrete floor without cracking it?