Question 934543
<pre>
Suppose the points are labeled with the letters A,B,C,...,Y

(A) A straight line is determined by two points.  There are C(25,2) choices of
pairs of those 25 letters.  That's {{{(25*24)/(2*1)}}} = 300 straight lines.

(B) A triangle is determined by three points which are not collinear.  There are
C(25,3) choices of groups of 3 of those 25 letters.  That's {{{(25*24*23)/(3*2*1)}}} = 2300 triangles.

Edwin</pre>