Answer:
2.5 m
Explanation:
Weight of billboard worker = 800 N
Number of ropes = 2
Length of scaffold = 4 m
Weight of scaffold = 500 N
Tension in rope = 550 N
The sum of the torques will be

The position of the person will be 2.5 m
Those are all "acceleration", caused by
unbalanced forces acting on the object.
We now that follow newton rules f=ma so net force equal to mass*acceleration=>f=50*1.5=75 N