O centroid
Step-by-step explanation:
In geometry, a median of a triangle is a line segment joining a vertex to the midpoint of the opposite side, thus bisecting that side. Every triangle has three medians, one from each vertex, and they all intersect each other at the triangle's centroid.
The answer is (B): A few positive particles bounced back because they were pushed away from the positive center.
20r + 60t
The greatest common factor we can factor from both of these terms is 20.
20(r + 3t). This is the final answer.
