What is more useful when it is broken?

What is the word or phrase?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

A donkey is behind another donkey
I'm behind that second donkey
But there is a whole nation behind me

It is a murder you can describe in a word.

A swan sits at the center of a perfectly circular lake. At an edge of the lake stands a ravenous monster waiting to devour the swan. The monster can not enter the water, but it will run around the circumference of the lake to try to catch the swan as soon as it reaches the shore. The monster moves at 4 times the speed of the swan, and it will always move in the direction along the shore that brings it closer to the swan the quickest. Both the swan and the the monster can change directions in an instant.
The swan knows that if it can reach the lake's shore without the monster right on top of it, it can instantly escape into the surrounding forest.

How can the swan successfully escape?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

I have feet, but no legs. Which animal Am I?

Rearrange the letters in "new door" to make one word.

It is a 5 letter word if you take away first letter it is something you get from sun, if you remove second letter you will get something to eat, if you remove third letter you get a word you use in pointing at and if you remove the fourth letter you get something to drink. What is it?