Wanna test your analytical skills ?

I just randomly landed over a good puzzle, and felt that it might serve as a treat to your brain cells. So, just grab a piece of paper and a pencil, ... and here you go, ....

Ten teachers are assigned to evaluate a multiple choice test. In order to secure the privacy of the examination, each teacher was given only the answers of some of the questions. The point is to guarentee the gathering of at least five teachers for getting answers to all of the questions. (That is to say, no combination of four or less teachers will be able to collect all the answers, whereas any combination of five or more teachers will be able to collect them all).

What is the minimum possible number of questions in this test and at least how many answers should be given to each teacher?

Kindly do not mention the answer in your comments. Thanks !

This puzzle has been taken from http://www.puzzleup.com/