Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

Once upon a time, there was a castle on a square island. The entire island was surrounded by a 14m wide trench. The Romans had wanted to invade the castle and had brought a few wooden planks along with them to facilitate themselves in crossing the moat. The planks were however found to be only 13m long.

The Romans still managed to cross the trench. How did they do it?

I am the first thing you need while camping.
I am always with the person named Marcos Valencia and Carrick.
But Pogba Zlatan and Rooney think I am wasteful and do not need me.
I am the second to the last thing to add when you are making a patch.

What am I?

The husband and wife were jogging in the morning. To match every two steps of the husband, the wife required three steps. If Both of them start with the here right foot. After how many steps do their left foot be together?

Whats the next number in the below number sequence pattern.

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

There are forty elephants and they have forty-fore heads. How can this be possible?

Why Wine Glass Stem is so long?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?