By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

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

Spot what is wrong here in below Picture?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

John was visiting his friend Jacob. He found out that his friend's wife had just killed a burglar in self-defense.
John asks Jacob about what happened and he told that "His wife was watching television when suddenly the bell rang. She thought that it is her husband Jacob but she found the burglar who attacked her instantly and she got so frightened that she killed the burglar immediately with the knife.
John asked the police to arrest his friend's wife. Why?

Complete the following series. It.s very logical:

1, 4, 5, 6, 7, 9, 11, __?

Can you find out the remainder when 3^300 is divided by 5?

Complete the table series riddle by finding the number that can replace "??".

John and his team plan to rob a safe. They got just one chance to break the code else the local police will be informed. Below are clues:
A) Exactly one number is perfectly placed: 9 8 1
B) Everything is incorrect: 9 2 4
C) Two numbers are part of the code of the safe but are wrongly placed: 0 9 3
D) One number is part of the code of the safe but is wrongly placed: 1 4 7
E) One number is part of the code of the safe but is wrongly placed: 7 8 3

I start and end with 500 and carry a 5 in my heart. But I require the first letter and the first number to be complete. I am the name of a King.

Who am I ?