Answer:
Actual mechanical advantage = force out / force in
250 N / 100 N = 2.5 force out is 2.5 X force provided
250 N * 10 m = 2500 Joules work output
100 N * 50 m = 5000 Joules work input
Efficiency is 2500 / 5000 = 50 %
Not sure what is meant by VR