I have eight fingers and two thumbs but I do not live. What Am I?

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?

What part of the chicken has the most feathers?

A California farmer owns a beautiful pear tree. He supplies the fruit to a nearby grocery store. The store owner calls the farmer to see how much fruit is available for him to buy. The farmer knows the main trunk has 24 branches. Each branch has exactly 12 boughs and each bough has exactly 6 twigs. Since each twig bears one piece of fruit, how many plums will the farmer be able to deliver?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

It is a six-letter word.
The first four letters are me.
The second and last letters are the same.
The fourth second and last letter is payment.

Who is it?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

What does this rebus riddle mean?

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.