In: Statistics and Probability
A box contains three fair coins and one biased coin. For the biased coin, the probability that any flip will result in a head is 1/3. Al draws two coins from the box, flips each of them once, observes an outcome of one head and one tail and returns the coins to the box. Bo then draws one coin from the box and flips it. The result is a tail. Determine the probability that neither Al nor Bo removed the biased coin from the box.