In a certain reading room, the ratio of men to women was 3:4. After leaving 2 girls, the ratio of men to women is 4:5. How many people are there in the reading room?
某阅览室原来男、女人数比为3：4，走了2名女生后，男、女人数比为4：5，求阅览室原有多少人？
<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">5 / 4</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(4/3) - (5/4)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">2 / (1/12)</gadget>
<output>24</output>

<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">24 / (3/7)</gadget>
<output>56</output>

<result>56</result>