Can you fill the blank with the correct number?

6 30 870 756030 _____

Why are all black people so quick ?

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

How many letters are in the alphabet?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

What happened when the wheel was invented?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

I am sure no one can have two things for dinner. what are they?

Which Burger Is Different in below image?

You need to pick one entry from pot A and one from pot B to have a perfect match. Can you do it?