The number of boys in the campus book reading room accounts for 2/5 of the total number of people. Later, 4 boys came and 4 girls left. Now the number of boys and girls is exactly equal. How many people were there in the reading room?
校园书阅览室男生人数占总人数的(2/5)，后来又来了4名男生，走了4名女生，现在男、女生人数正好相等，阅览室原来多少人？
<gadget id="calculator">4 + 4</gadget>
<output>8</output>

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

<gadget id="calculator">1 - (2/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">8 / (1/5)</gadget>
<output>40</output>

<result>40</result>