math(Please help Urgent!!!)
posted by Abbey .
In triangle ABC, D is the centroid and M is the midpoint of segment AC. If BD=10 and DM=2x+1, find MB. Answer choices: 2 , 9.5, or 15.

the centroid cuts the median in the ratio of 2:1, the shorter part towards the midpoint of the side.
so 10/2 = (2x+1)/1
solve to get x=2
so DM = 5 and MB = 5+10 = 15