Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

Suppose you are a girl candidate and sitting in an interview. Suddenly the interviewer asks you, 'What if one morning you wake up and find out that you are pregnant?

How will you reply to such a question?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

Solve the following series:
AZ, GT, MN, __, YB

Move four matchsticks to the below square to form three squares?