Good Riddles

Question: What is at the end of a rainbow?

Question: 500 is at my end and my start, yet 5 is at my heart.
The first letter and the first number make me complete.
My name is that of a king.

What am I?

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?

Question: Those who make this item, don't use it. Those who BUY this item, have no need for it. But those who USE this item, never see it. What is the item?

Question: A grandfather has a broken grandfather clock that is off by a minute every hour (too fast). He figures out a way, while keeping it running at the same rate, to make the clock say the correct time twice a day.

How could he do this?