Another Monday Puzzler

Another little brainteaser I've adapted from a recent Quora.com mathematics thread:

You receive a letter on a Friday that is either a rejection letter or an acceptance letter to medical school. You have a wonderful weekend planned and don't want bad news interfering with it. Can you devise a way to learn the contents of the letter BUT ONLY if it is good news?
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.answer below
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answer:

1. Have a friend open the letter.
2. Instruct them that IF it is good news they are to flip a coin and tell you the news ONLY if it comes up heads, otherwise tell you nothing.
3. AND, if it's bad news, tell you nothing.

This way you will either be told good news, OR STILL have 33% hope for good news, if they tell you nothing.