Asegment with endpoints a (4, 2) and c (1, 5) is partitioned by a point b such that ab and bc form a 1: 3 ratio. find b.
a. (1, 2.5)
b. (2.5, 3.5)
c. (3.25, 2.75)
d. (3.75, 4.5)

With the given ratio, 1: 3, one-fourth of the difference of the abscissas and ordinates should be added to the coordinates of point a to determine  the unknown  coordinates of point b. 
 
  abscissa             (1 - 4) / 4 = -3/4       ;     4 + (-3/4) = 3.25
  coordinate           (5 - 2) / 4 = 3/4       ;     2 + (3/4) = 2.75

thus, the answer of this question is letter c.