Good Riddles

Question: You bury me when I'm alive,
and dig me up only when I die.

What am I?

Question: Crawls over pages and fells wild beasts.
Helps guide you along in your home and on streets.

What is it?

Question: There are two planes. One is going from New York to London at a speed of 600 MPH. The other is traveling from London to New York at a speed of 500 MPH.

When the planes meet which one will be closer to London?

Question: You have 7 tennis balls that are all identical but one of them is slightly lighter than the others.

Using a balance scale and only two separate weightings, how can you find the light tennis ball?

Question: Little Johnny's teacher asks him, "If I gave you two cats, then two more, and two more cats; how many would you have?"

Little Johnny replies, "Seven!"

His teacher asks him again more slowly, "If I gave you two cats, then two more, and two more cats; how many would you have?"

But again Little Johnny replies, "Seven!"

Next she asks, "If I get two cats, then two more, and two more cats; how many would I have?"

Little Johnny replies, "Six!"

"Good Job Johnny! Now if I gave you two cats, then two more, and two more cats; how many would you have?"

Johnny thinks for a second, "Seven."

But Johnny is not wrong. Why?