Can you fill the blank with the correct number?

6 30 870 756030 _____

I am the fastest animal but cannot climb the tree. What am I?

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

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

It's a 7-letter word.
If we remove 1 letter from it, it remains the same.
If we remove 2 letters from it, it remains the same.
If we remove 3 letters from it, it remains the same.
If we remove all the letters from it, still it remains the same.
What is it?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

In a contest, four fruits (an apple, a banana, an orange, and a pear) have been placed in four closed boxes (one fruit per box). People may guess which fruit is in which box. 123 people participate in the contest. When the boxes are opened, it turns out that 43 people have guessed none of the fruits correctly, 39 people have guessed one fruit correctly, and 31 people have guessed two fruits correctly.
How many people have guessed three fruits correctly, and how many people have guessed four fruits correctly

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?