The number of male employees in a workshop accounts for 3/7 of the total number. After 20 male employees were transferred to support key projects, the ratio of male and female employees was 1:3. How many male employees were there?
一个车间男职工人数占总数的(3/7)，因支援重点工程调走男职工20人后，男、女职工人数的比是1：3，原来有男职工多少人？
<gadget id="calculator">7 - 3</gadget>
<output>4</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(3/4) - (1/3)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">20 / (5/12)</gadget>
<output>48</output>

<gadget id="calculator">48 * (3/4)</gadget>
<output>36</output>

<result>36</result>