Question

There are 10 points in a plane, out of which 4 of them are collinear.
(a) How many straight lines can be produced?
(b) How many triangles can be produced?​

Answer 1

Answer:

b) 116

a) 40

Step-by-step explanation:

2 points when joined in a plane will make 1 line If the total number of point is 10, the total number of line

⇒

10

C

2

But 4 points are collinear, so the lines make with these 4 points are same.

Hence there is 1 common line joining the 4 collinear point Finally, The number of straight line =

10

C

2

−

4

C

2

+1

=45−6+1

=40