The number of female workers in a certain factory is 80% of the number of male workers. Later, 15 female workers were transferred. At this time, the female workers outnumbered the male workers by 30%. How many male workers are there in this factory?
某厂女工人数是男工人数的80%，后来又调15名女工，这时女工比男工多30%，这个工厂有多少男工？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(3/10) - (4/5)</gadget>
<output>-1/2 = around -0.5</output>

<gadget id="calculator">1 + (-1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">15 / (1/2)</gadget>
<output>30</output>

<result>30</result>