SOLUTION: A coin is biased so that the probability that it lands showing heads is 2/3.The coin is tossed three times.Find the probability that: a)No heads are obtained. b)More heads than t

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Question 924020: A coin is biased so that the probability that it lands showing heads is 2/3.The coin is tossed three times.Find the probability that:
a)No heads are obtained.
b)More heads than tails are obtained.

#PleaseHelp
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Look at the possible outcomes.
HHH - 3 heads - P=%282%2A2%2A2%29%2F%283%5E3%29=8%2F27
HHT - 2 heads - P=%282%2A2%2A1%29%2F%283%5E3%29=4%2F27
HTH - 2 heads - P=%282%2A1%2A2%29%2F%283%5E3%29=4%2F27
HTT - 1 heads - P=%282%2A1%2A1%29%2F%283%5E3%29=2%2F27
THH - 2 heads - P=%281%2A2%2A2%29%2F%283%5E3%29=4%2F27
THT - 1 heads - P=%281%2A2%2A1%29%2F%283%5E3%29=2%2F27
TTH - 1 heads - P=%281%2A1%2A2%29%2F%283%5E3%29=2%2F27
TTT - 0 heads - P=%281%2A1%2A1%29%2F%283%5E3%29=1%2F27
a) P%28TTT%29=1%2F27
b) P=+%288%2B4%2B4%2B4%29%2F27=20%2F27