Suppose you are given a six-sided die, that might be biased in an unknown way.

Explain how to use die rolls to generate unbiased coin flips, and determine the expected number of die rolls until a coin flip is generated.

Now suppose you want to generate unbiased die rolls (from a six-sided die) given your potentially biased die.

Explain how to do this, and again determine the expected number of biased die rolls until an unbiased die roll is generated.

For both problems, you need not give the most efficient solution; however, your solution should be reasonable, and exceptional solutions will receive exceptional scores.