Probability Doubt

Posted by Xiang on May 28, 2013; 6:02am
URL: http://discussion-forum.276.s1.nabble.com/Probability-Doubt-tp7581368.html

please give the logic behind solving. I got the answer but I am not too sure if i have been thinking right.

THERE ARE 12 POINTS IN A PLANE OF WHICH 5 ARE COLLINEAR. HOW MANY LINES CAN BE CONSTRUCTED BY JOINING 2 POINTS?
ALSO, HOW MANY TRIANGLES ARE POSSIBLE.

Thanks :)