The number of circles that can be drawn out of 10 points of which 7 are collinear is
Choose the correct choice from the following answers:
A) 130
B) 85
C) 45
D) 72
E) 82
For drawing a circle we need 3 non collinear points.   This can be done in:   3C3 + 3C2 x 7C1 + 3C1 x 7C2 = 1 + 21 + 63= 
<gadget id="calculator">1 + 21 + 63</gadget>
<output>85</output>
85   ANSWER:85
<result>B</result>
The number of circles that can be drawn out of 10 points of which 7 are collinear is