Which of the following represents the coordinates of point a?

The coordinates of A will be (2P +M)/3
= (2(16, 14) +(1, 4))/3 = (33/3, 32/3) = (11, 32/3)

The appropriate choice is
  (C) (11, 32/3)


You will note that the coordinates of A are the weighted average of the coordinates of the end points. The weighting is the reverse of the ratio of the line segments. That is, the point adjacent to the shortest segment gets the highest weighting. (This is typical of the solution to "mixture" problems.)