How can you leave a room with two legs and return with six legs?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

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

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

I have branches, but no fruit, trunk or leaves. What am I?

I am something people love or hate. I change peoples appearances and thoughts. If a person takes care of them self I will go up even higher. To some people I will fool them. To others I am a mystery. Some people might want to try and hide me but I will show. No matter how hard people try I will Never go down. What am I?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

If eleven plus two equals one, what does nine plus five equal?