Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?

I look at you, you look at me, I raise my right, you raise your left. What am I?

What number when divided in half becomes zero?

You need to move three matchsticks to form three squares. Can you do it?

Can you find the key in the picture below?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

A man is found hanging dead from the ceiling of a room. The room’s dimensions are 15 x 15 x 15. The man is only 6ft tall and the rope was only 2ft long. There are no windows and only one door to the room. The door is bolted shut from the inside, and a puddle of water is under the man. How did he kill himself?

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

Two old friends, Jack and Bill, meet after a long time.

Three kids
Jack: Hey, how are you, man?
Bill: Not bad, got married and I have three kids now.
Jack: That's awesome. How old are they?
Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.
Jack: Cool..But I still don't know.
Bill: My eldest kid just started taking piano lessons.
Jack: Oh, now I get it.

How old are Bill's kids?