Sara has three coins which you believe to be fair, and are labeled #1, #2, and #3. Suppose Sara flips all three coins and tells you that at least 2 of them landed heads. Given that you believe each...

Sara has three coins which you believe to be fair, and are labeled #1, #2, and #3. Suppose Sara flips all three coins and tells you that at least 2 of them landed heads. Given that you believe each coin's probability of landing heads is irrelevant to how the other coins land, what is the probability that coin #1 landed on Head?