About 400 marbles. You simply set up a proportion and solve it as I did in the photo attached.
129/43x100=300
129 is 43% of 300
Collinear points lie on the same line. So, you must look for other points that lie on the line that connects A and N. If you start from A and continue along that line, you can see that, after N, you will meet points M and F.
So, those points are collinear with A and N.
Jeff is correct because:
2 sides of a triangle must always be longer than the other side, so:
12+8>19
19+8>12
12+19>8
Since all of them are true, Jeff is correct
