Final answer:
The efficiency of a lever can be calculated using the formula: Efficiency = (output force / input force) * 100%. In this case, the input force is 11 N and the resistance arm lifts a weight of 40 N.
Step-by-step explanation:
The efficiency of a lever can be calculated using the formula:
Efficiency = (output force / input force) * 100%
In this case, the input force is 11 N and the resistance arm lifts a weight of 40 N. So, the output force is 40 N. Plugging in the values, we have:
Efficiency = (40 N / 11 N) * 100% = 363.6%
Since efficiency cannot exceed 100%, the answer would not be any of the given options (a, b, c, d).