排列组合 Flipping a fair coinFlipping a fair coin.Assume that the coin is flipped 7 times.What is the probability that both heads and tails occur?Thank you~

排列组合 Flipping a fair coinFlipping a fair coin.Assume that the coin is flipped 7 times.What is the probability that both heads and tails occur?Thank you~ Flipping heck! 向概率牛求教一道概率题Two players take turns flipping a fair coin.The game ends when the same outcome occurs on three flips in a row.Whichever player fli pped the coin last,wins.For example:Player 1 flips HPlayer 2 flips TPlayer 1 flips TP A fair weather friend a fair weather friend a fun fair翻译 pay a fair price hold a job fair a fair amount fair fair fair fair nancy is a fair girl. what a fair red blood! wish you a fair wind 请问“a fair amount”是什么意思? that's a fair question.fair question是什么意思?