Best riddles

I can run, but not walk. Thought is not far behind me. What am I?

Two planes take off at the same exact moment. They are flying across the Atlantic. One leaves New York and is flying to Paris at 500 miles per hour. The other leaves Paris and is flying to New York at only 450 miles per hour. Which one will be closer to Paris when they meet?

What has an eye but can not see?

A doctor and a bus driver are both in love with the same woman, an attractive girl named Sarah. The bus driver had to go on a long bustrip that would last a week. Before he left, he gave Sarah seven apples. Why?

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

A king has no sons, no daughters, and no queen. For this reason he must decide who will take the throne after he dies. To do this he decides that he will give all of the children of the kingdom a single seed. Whichever child has the largest, most beautiful plant will earn the throne; this being a metaphor for the kingdom.At the end of the contest all of the children came to the palace with their enormous and beautiful plants in hand. After he looks at all of the children's pots, he finally decides that the little girl with an empty pot will be the next Queen. Why did he choose this little girl over all of the other children with their beautiful plants?

Four men were fishing in a boat on the lake. The boat turned over and all four men sank to the bottom of the lake. And yet, not one single man got wet. How is this possible?

The thunder comes before the lightning; the lightning comes before the clouds. The rain dries everything it touches.

I repeat only the last word you say. The more I repeat, the softer I got. I cannot be seen but can be heard. What am I?

In a supermarket, the first 25 customers of the day purchased an average of two items each. After a further 15 customers, the average number of items purchased by each customer rose to eight. What was the average number of items purchased by the last 15 customers only?