Answer: The answer is 50%.
Step-by-step explanation: Given that the factory produces 126 articles in a day. After retooling, the production of the articles increased and they started producing 189 articles in a day. We need to calculate the percent increase in labour productivity.
We have,
Percent Increase in labour productivity will be equal to the percent increase in the number of articles.
Increase in the number of articles after retooling = 189 - 126 = 63.
Therefore, percent increase in the number of articles is given by
Thus, the labour productivity increased by 50%.