When we see 2 but call 10?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

Make a sentence consisting of three words that have the whole alphabet.

The answer I give is yes, but what I mean is no. What was the question?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

You are on a Boat in the mid of a river. You have two cigarettes with you. One of these two you have to light, how will you light the cigarette?

When is the top of a mountain similar to a savings account?

Name a key which is hardest to turn.

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

What can jump higher than a building?