Can you fill the blank with the correct number?

6 30 870 756030 _____

What jumps when it walks and sits when it stands?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

A Man gave one of his sons 10 cents and another son was given 15 cents. What time is it?
Hint: Figure out the relation between time and number, is not so easy..:)

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

What am I?

Can you tell a 3D object that has just two surfaces?

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

What always comes into a house through the keyhole?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?