Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

There once were seven dwarfs who were all brothers. They were all born two years apart. The youngest dwarf is seven years old. How old is his oldest brother?

My location can be determined by the below rebus.
So where am i ?

A man was just doing his job when his suit was torn. Why did he die three minutes later?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

what's the probability of getting a king or a queen from a pack of 52 cards?

Cristina leaves home and then she makes exactly 3 left turns and returns home where she found 2 girls wearing the mask.

Who are these two masked girls?

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?