Calculate the percent change in productivity for the following situations. Round all percentage answers (including intermediate calculations) to four decimal places (i.e. 0.1234 or 12.34%).
a) Increase labor hours by 25%, resulting in a 50% increase in output.
b) Your output doubles from a 65% increase in workforce.
c) Triple the number of machines used to produce an item, resulting in a 90% increase in sales.