In a certain factory, female workers accounted for 1/5 of the total number of workers. Later, 20 female workers were transferred in. At this time, female workers accounted for 1/2 of the male workers. How many workers are there in the factory?
某厂女职工占工人总数的(1/5)，后来又调来20名女工，这时女工是男工人数的(1/2)，问厂里现有工人多少名？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(1/5) / (4/5)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/2) - (1/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">20 / (1/4)</gadget>
<output>80</output>

<gadget id="calculator">80 * (1/2)</gadget>
<output>40</output>

<gadget id="calculator">80 + 40</gadget>
<output>120</output>

<result>120</result>