Please please help!!!!

Answer:
AM = 5
Step-by-step explanation:
The centroid of a triangle divides each median into two segments in a 2:1 length ratio. The segment closer to the vertex is the longer one.
PM:AM = 2:1
PM/AM = 2/1
PM = 10
10/AM = 2/1
2AM = 10
AM = 5