The circumcenter is the center of a triangle's circumcircle (circumscribed circle over triangle). It can be found as the intersection of the perpendicular bisectors.
The incenter is the center of the incircle (inscribed circle into a triangle) of a triangle. The incenter can be constructed as the intersection of angle bisectors.
Centroid is the point where the three medians of the triangle intersect.
The intersection of the three altitudes of a triangle is called the orthocenter.
Since three medians intersect at point which divides each median into 2:1 ratio, the answer is centroid.
15 Bags. If he buys 15 two-pound bags he will have thirty pounds of peanuts, enough to fill thirty six 5/6-pound bags without having any peanuts left over.