What is the Surname of Barbie Doll?

You can hear me, but you can't touch or see me.

What am I?

What number do you get when you multiply all of the numbers on a telephone's number pad?

Using eight eights and addition only, can you make 1000?

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

( ) + ( ) + ( ) = 30

Replace the question mark with the correct number.

What is the word or phrase?

Sherlock breaks into a crime scene. The victim is the owner who is slumped dead on a chair and have a bullet hole in his head. A gun lies on the floor and a cassette recorder is found on the table. On pressing the play button, Sherlock hears the message 'I have committed sins in my life and now I offer my soul to the great Lord' and followed a gunshot Sherlock smiles and informed the police that's its a murder.

Why did he think so?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

Move four matchsticks to the below square to form three squares?