D=4n-2, d+2=4n-2+2, d+2=4n
(d+2)/4=(4n)/4, 1/4d+1/2=n
n=1/4n+1/2
size 3=
n=1/4*3/1=3/4, 3/4+1/2=5/4=1 1/4
size 3=1 1/4
size 6=
n=1/4*6/1=6/4, 6/4+1/2=8/4=2
size 6=2
size 10=
n=1/4*10/1=10/4, 10/4+1/2=12/4=3
size 10=3
Using two point form
y-5/-4-5=x-10/13-10
rearrange to get 3x+y-35=0
The answer should be 10 I think, because if u multiply 250 * 4% u get 10.
Hope I'm right.