Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Solve The below Equation:

ALFA + BETA + GAMA = DELTA

Two friends were betting. One said to the other, "The coin will be flipped twenty times and each time the coin lands on the head, I will give you $2 and each time it lands on the tale, you will give me $3." After flipping the coin twenty times not a single penny was exchanged among them.

How many times did the coin land on heads?

Which of the following words don't belong in the group and why?
CORSET, COSTER, SECTOR, ESCORT, COURTS

If six children and two dogs were under an umbrella, how come none of them got wet?

A girl was sitting in her hotel room when she heard a knock on the door. She opened the door and found that a man was standing outside.
The man said, "Oh! I am really sorry, I thought this was my room."
He then walked through the corridor to the elevator. The girl did not know the man. She closed her door and called security asking them to apprehend the man.
What made her suspicious of that man? He might have been genuinely mistaken.

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

What kind of band never plays music?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?