I think there is some mistake with this question. This is because, if D was the midpoint of AB, then CD and BE would have been medians and N would have been the centroid of this triangle. But N divides a median in the ratio 2 : 1. So, there is some mistake in this question.

CIRCLE image.png 65.73 KBHOW TO SAY THAT D IS THE MID POINT

CIRCLE image.png 65.73 KBHOW TO SAY THAT D IS THE MID POINT