Question 742381
Three coins are tossed. What is the probability that 
at least one coin shows heads?
<pre>
Think of all the possible ways:

   1st       2nd       3rd        Does at least
   coin      coin      coin      one show heads? 
1.  H         H         H             yes
2.  H         H         T             yes
3.  H         T         H             yes         
4.  H         T         T             yes
5.  T         H         H             yes          
6.  T         H         T             yes
7.  T         T         H             yes
8.  T         T         T             no

Answer: 7 times out of 8 or {{{7/8}}}.

Edwin</pre>