Question 907701
<pre>
Since 18 = 2*3*3, then for an integer not to be divisible by 18,
yet divisible by 2 and 3 (and therefore 6), it must be even and
not be divisible by 3*3 or 9.  They're all even, but the only 
one in the list that isn't divisible by 9 is a. 48.

Edwin</pre>