What number should come in place of the question mark below?

I cannot talk, but I always reply when spoken to. What am I?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

You bought me for dinner but never eat me. What am I?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

By using 'because' continuously three times, can you make an English statement ?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

On a beautiful Sunday morning, You ordered a hot tea to your hotel room and suddenly you remember an important thing that needed to be done right now will take around 3 minutes to complete.
Like most people you like your tea to be hot while drinking so, when should you pour cream in the tea?
1. straight away
2. Just people, you drink the team
3. Its does not matter

John was so frustrated to be the suspect of being a sleeper terrorist that he shoot himself right between the eyes with a revolver in his toilet. The revolver and the bullets were accurate. Minutes later John walks out of the toilet unharmed.
How can this be possible?

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?