Segment partitioned
1:3 ratio means segment is partitioned in 4 parts
Then , now find distance between A and C
X distance = 5-2 = 3
Y distance = 1-4 = -3
Now divide by 4, and from A coordinates(4,2) rest (3/4,-3/4) to find B coordinates
Then as a consecuence B coordinates are
B = (4-(3/4) , 2-(3/4)) = ( 13/4, 5/4)