Can you fill the blank with the correct number?

6 30 870 756030 _____

What is so fragile that saying its name breaks it?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

I organized a small get together at my home.
In the party , i have a barrel with some whiskey in it.

Suddenly Guest 1 say 'I bet this barrel of whiskey is more than half full'.
'No, it's less than half full' Guest 2 replied.

I don't have any measuring instrument and without removing whiskey from it , how can i determine which of the guest is right ?

I have eight fingers and two thumbs but I do not live. What Am I?

How can you tell a raw egg from a hard-boiled egg?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?