Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

Using Only Five 5's and any mathematical operator make sum as 37

What does an Island and the letter T have in common?

Seven Robbers robbed a bank and hide the coins in a lonely place.
They decide to divide the money equally the next morning. Two greedy robbers decided to cheat the others and reach the place at night. They equally divided the coins between them, one coin left. So they called another robber and then they decided to divide equally among the three. Sadly again one coin left. The same thing happened to the 4th 5th and the 6th robber.
However, when the 7th robber reached in the morning, they can divide the coins equally.

How many coins were there in total?

You walk into a creepy house by yourself. There is no electricity, plumbing, or ventilation. Inside you notice 3 doors with numbers on them. Once you open the doors you will die a particular way. Door No.1 You’ll be eaten by a lion who is hungry. Door No.2 You’ll be stabbed to death. Door No.3 There is an electric chair waiting for you. Which door do you pick?

I can be cracked, made, told, and played. What am I?

It is a nine-letter word.
The exact opposite of the phrase "friendly and outgoing"
It contains the word "over".
It starts will a vowel.

What is it?