Question 715814
<pre>
The numerator of the probability is the number of ways she can
succeed in picking a number greater than 600.

There are 4 ways she can pick the first digit as 6,7,8, or 9
That leaves 8 ways she can pick the second digit.
That leaves 7 ways she can pick the third digit.

So there are 4򊤋 ways she can pick a number larger than 600.

The denominator of the probability is the number of ways she can
pick any number whether smaller or larger than 600.

There are 9 way she can pick the first digit.
That leaves 8 ways she can pick the second digit.
That leaves 7 ways she can pick the third digit.
 
So there are 9򊤋 ways she can pick any nunber (whether smaller 
or larger than 600).

So the probability that she will succeed in picking a number greater
than 600 is the fraction

     {{{(4*8*7)/(9*8*7)}}} = {{{(4*cross(8)*cross(7))/(9*cross(8)*cross(7))}}} = {{{4/9}}}

Edwin</pre>