First we define a reference system.
Let's assume the horizontal axis as positive towards the right.
Suppose Kiley and Jermaine pull the rope to the left, while Gunther pulls the rope to the right.
The equilibrium equation is given by:
Where,
F: force with which Gunther pulls the rope.
Clearing F we have:
The positive sign indicates that Gunther pulls to the right.
Answer:
A force that would result in a balanced force for the game is: