Answer:
η = 0.882 = 88.2 %
Step-by-step explanation:
The efficiency of the pulley system can be given as follows:

where,
η = efficiency of pulley system = ?
W_out = Output Work = (600 N)(0.6 m) = 360 J
W_in = Input Work = (35.7 N)(11.43 m) = 408.051 J
Therefore,

η = 0.882 = 88.2 %