There are 68 total points.
Let the points held by the contestants be
x for Eric,
y for Sheena,
z for Yael.
Therefore
x + y + z = 68 (1)
Sheena has three fewer points than Yael, Therefore
y = z - 3 or
y - z = -3 (2)
Eric has half as many points as Sheena. Therefore
x = (1/2)y, or
2x = y (3)
Add (1) and (2).
x + 2y = 65 (4)
Substitute (3) nto (4).
x + 2(2x) = 65
5x = 65
x = 13
y = 2x = 26
From (2),
26 - z = -3
z = 29
Answer: Yael has 29 points
