I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

A King wants to send the diamond ring to his girlfriend securely. He got multiple locks and their corresponding keys. His girlfriend does not have any keys to these locks and if he sends the key without a lock, the key can be copied in the way. How can King send the ring to his girlfriend securely?

Can you replace the question mark with the correct number?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

Andrew sees a very rare bird named "Ruppell's vulture". Soon Andrew was dead. Can you explain the mystery, Mr. Sherlock?

Can you make the below equation true by using any three numbers from "1, 3, 5, 7, 9, 11, 13 and 15"?

( ) + ( ) + ( ) = 30

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

O_er_t_o_

Complete the missing letters of the given word.

It is a nine-letter word.
The exact opposite of the phrase "friendly and outgoing"
It contains the word "over".
It starts will a vowel.

What is it?