Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

A police officer was passing by when he saw a guy hiding. He walked up to him and genially asked, "What is your name?"

"Shut up!" the boy responded.

"Where are your manners?" asked the outraged police officer.

"Up that tree," said the boy discourteously, directing to a neighbouring tree.

You're looking for trouble, aren't you?" said the police officer.

"No, trouble is looking for me!" the boy answered solemnly.

Why is the boy behaving like this?

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

What is the centre of gravity?

What is the word or phrase below?
R | E | A | D

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?