What is black when you buy it, red when you use it, and gray when you throw it away?

What can go up a chimney down, but can’t go down a chimney up?

What is harder to catch the faster you run?

In a football game, Christina defeated Teresa by 2 - 0 but no man from either side scored. How can this be possible?

The husband and wife were jogging in the morning. To match every two steps of the husband, the wife required three steps. If Both of them start with the here right foot. After how many steps do their left foot be together?

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?

If,

20 % 5 = 24

21 % 7 = 33

42 % 6 = 67

Then;

66 % 6 = ?

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?

You are playing a game with your friend Jack. There are digits from 1 to 9. You both will take turn erasing one digit and adding it to your score. The first one to score 15 points will win the game.

Would you want to play first or second?

PS: The sum should be exactly 15.

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?