Can you fill the blank with the correct number?

6 30 870 756030 _____

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _

If eleven plus two equals one, what does nine plus five equal?

One day, I thought of ways that can be used for creating a palindrome. So I decided that I will turn into a larger number by adding the reversed digits to the original number and keep doing it till I finally obtained a palindrome.

I am not sure if this process will always result in a palindrome eventually but I was able to produce a four-digit palindrome. Can you guess my starting number?

Can you make the below equation true by using any three numbers from "1, 3, 5, 7, 9, 11, 13 and 15"?

( ) + ( ) + ( ) = 30

Decode below rebus
D
N
A
T
S , D

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.