If the co-ordinates of the endpoints of a line segment are (a,b) and (c,d), then the point 1/3 of the way from (a,b) to (c,d) has co-ordinates: abscissa (2/3)a+(1/3)c and ordinate
(2/3)b+(1/3)d.
From this relationship you should be able to solve the problem...and the answer (1,-4) is correct.