Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

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

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?

How many letters are in the alphabet?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

What goes up but never comes down?

Kohli and Dhoni decided to have a paintball match.
Kohli told Dhoni, "Sir it is not right as you got thrice the paintballs I have".

Dhoni instantly gives Kohli 10 hit paintballs.
Kohli replied, "Sir, I believe you still have twice the paintballs than I have".

Dhoni gives "?" more paintballs to Kohli.
Kohli replied, "Sir it is even now, Let us have a match".

What is "?".

John gave half of the apples he had plus one more to Jacob. He gave half of the remaining ones plus one more to James. Now, John was left with just one apple.

Can you find out how many did he have in the beginning?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

what does the below math rebus puzzle mean?