Among the students reading in the reading room, female students accounted for (3/5). After 3 female students walked out of the reading room, among the students reading, female students accounted for (4/7). How many students were reading in the reading room? ?
阅览室看书的同学中，女同学占(3/5)，从阅览室走出3位女同学后，看书的同学中，女同学占(4/7)，原来阅览室一共有多少名同学在看书？
<gadget id="calculator">5 - 3</gadget>
<output>2</output>

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

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

<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">(3/2) - (4/3)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">3 / (1/6)</gadget>
<output>18</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">18 / (2/5)</gadget>
<output>45</output>

<result>45</result>