There are 10 points in a plane, out of these 6 are collinear. The number of triangles formed by joining these points, is

Options

A. `N gt 190`
B. `N le 100`
C. `100 lt N le 140`
D. `140 lt N le 190`

Answer

B

Explanation

Number of triangles`=.^(10)C_(3)-.^(6)C_(3)`
`impliesN=(10*9*8)/(1*2*3)-(6*5*4)/(1*2*3)impliesN=120-20impliesN=100`
`thereforeN le 100`