Question

In tossing three fair coins together what is the probability of getting atmost one tail.

Answer 1

In tossing three fair coins together, the sample space is given by:
$S=\{HHH,HHT,HTH,THH,HTT,THT,TTH,TTT\}$
$\therefore n\left(S\right)=8$
Let $C$ be the event of getting at-most one tail

Then, $A=\{HHH,HHT,HTH,THH\}$
$\therefore n\left(C\right)=4$
$\therefore P\left(C\right)=\frac{n\left(C\right)}{n\left(S\right)}=\frac{4}{8}$