SOLUTION: A coin is tossed three times. Find the probability of: a. getting either all tails or getting a tail exactly once. b. getting all heads or getting a head and two tails.

Algebra ->  Probability-and-statistics -> SOLUTION: A coin is tossed three times. Find the probability of: a. getting either all tails or getting a tail exactly once. b. getting all heads or getting a head and two tails.      Log On


   

Question 1153771: A coin is tossed three times. Find the probability of:
a. getting either all tails or getting a tail exactly once.
b. getting all heads or getting a head and two tails.
Answer by ikleyn(52879) About Me  (Show Source):
You can put this solution on YOUR website!
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The sample space is this set of 8 elements

    1.   TTT

    2.   TTH

    3.   THT

    4.   THH

    5.   HTT

    6.   HTH

    7.   HHT

    8.   HHH



(a)  Favorable set (a) is  n1, n4, n6, n7.   In all, there are 4 favorable elements.


     Therefore,  P = favorable%2Ftotal = 4%2F8 = 1%2F2 in this case.    ANSWER



(b)  Favorable set (b) is  n8, n2, n3, n5.   In all, there are 4 favorable elements.


     Therefore,  P = favorable%2Ftotal = 4%2F8 = 1%2F2 in this case.      ANSWER