Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

81 x 9 = 801. What must you do to make the this equation true?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

What is the end of everything?

Which is the smallest number that you can write using all the vowels exactly once?

You order chicken wings at KFC in the boxes of 6, 9 and 20. What is the largest number of wings that you cannot obtain by buying in any combination of the boxes?

Why Wine Glass Stem is so long?

What question can you never answer yes to?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Why do Chinese men eat more rice than Japanese men do ?