Triangle question (1 Viewer)

[alewe]

How would you get the answer, when I tried I got 412

 

[WeiWeiMan]

How would you get the answer, when I tried I got 412
View attachment 44299

15C3 - 5 x 3c3 - 3 x 5c3 = 420 hence C

 

[alewe]

But what about the diagonals

 

[alewe]

3 going both ways, so minus another 6, then minus another 2 for the long diagonals going over the whole grid, giving 412?

 

[WeiWeiMan]

But what about the diagonals

forgot those existed mb
crazy for picking that up damnnn
maybe just wrong solutions ngl
your answer seems fine

 

[Sethio]

Is it 414?
15C3 - 3x5C3(rows making 3 colinear points) - 5x3C3(columns making 3 colinear points) - 3 (diagonals left to right) - 3 (diagonals right to left) = 414

The reason i don't include the 2 spanning across the whole grid is because they don't look colinear per se. I think the middle dot spans a small angle above the end dots.

 

[WeiWeiMan]

Is it 414?
15C3 - 3x5C3(rows making 3 colinear points) - 5x3C3(columns making 3 colinear points) - 3 (diagonals left to right) - 3 (diagonals right to left) = 414

The reason i don't include the 2 spanning across the whole grid is because they don't look colinear per se. I think the middle dot spans a small angle above the end dots.

nah but if the dots are equally spaced apart the diagonals are collinear

line here is y=-1/2 x + 2 which passes thru (0,2), (2,1) and (4,0)

 

[Sethio]

oh then 412 my bad. there def aint 6 more colinear cases.

 

[alewe]

@Yananisback69 you said you did all the questions in this paper, what did you get?