SOLUTION: A coin is tossed 3 times and let X be the number of heads appearing. The probability that 1 head will appear is?

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Question 1117491: A coin is tossed 3 times and let X be the number of heads appearing. The probability that 1 head will appear is?
Found 2 solutions by ikleyn, Shin123:
Answer by ikleyn(52778) About Me  (Show Source):
You can put this solution on YOUR website!
.
The complement probability is the probability to have the reverse side in all 3 tosses, which is equal to  %281%2F2%29%5E3 = 1%2F8.


Therefore, the probability under the question is  1-1%2F8 = 7%2F8.



Answer by Shin123(626) About Me  (Show Source):
You can put this solution on YOUR website!
There are 2%5E3=8 possible incomes. And there are 3 incomes that have exactly 1 head (1st coin has head,2nd has head,or 3rd makes head). Therefore, the probability is 3%2F8. The other tutor @ikleyn thought of the probability of at least 1 head, but the problem clearly questions about the probability of

1

head.