Question 983946
In a singing contest there are 6 finalists: Ari, Bella, Calli, Della, Ella, and
Fits. What is the probability that Ari will perform immedietly before Bella ?
(Express answer as a fraction in lowest terms)
<pre>
The number of arrangements of these six things 

{A,B,C,D,E,F}

is 6!.

The number of arrangements of these five things

{(AB),C,D,E,F}, where A is immediately before B

is 5!

So the probability is 5! out of 6! or {{{5!/6!=(5*4*3*2*1)/(6*5*4*3*2*1)=(cross(5)*cross(4)*cross(3)*cross(2)*1)/(6*cross(5)*cross(4)*cross(3)*cross(2)*1)=1/6)}}}

Edwin</pre>