which of the following could be used to measure the efficiency of labour?

The input-output ratio could be used to measure the efficiency of labour. This ratio compares the amount of input used to produce a certain amount of output. In other words, it measures how much input, such as labour, capital, and materials, is required to produce a given amount of output. If the input-output ratio is low, it means that less input is needed to produce the same amount of output, which indicates higher labour efficiency. For example, if a factory can produce 100 units of a product using 10 workers and another factory can produce the same 100 units using only 8 workers, the second factory is more efficient because it uses less labour input to produce the same output. Therefore, the input-output ratio is a useful measure for assessing the efficiency of labour.