8 points are marked on a straight line and another 7 points are marked on a second straight line with no points in common. How many triangles can be constructed with vertices from among the above points?  Choose the correct option:  A) 264  B) 91  C) 168  D) 196  E) 264
Solution: select 2 from 8 and one from 7 + select 2 from 7 and 1 from 8   8C2*7C1 + 7C2*8C1   = 196+ 168= 
<gadget id="calculator">196+ 168</gadget>
<output>364</output>
364   264nswer : 264
<result>A</result>
8 points are marked on a straight line and another 7 points are marked on a second straight line with no points in common. How many triangles can be constructed with vertices from among the above points?