Female students in the extracurricular group originally accounted for (2/5) of the whole group. After adding 3 students, female students accounted for (1/2) of the whole group. So how many people were there in the extracurricular group?
课外小组女同学原来占全组人数的(2/5)，加入3个同学后，女同学就占全组人数的(1/2)，那么课外小组原来有多少人？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 3</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">3 - (3/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(3/2) / (1/10)</gadget>
<output>15</output>

<result>15</result>