The ratio of the number of extracurricular books between Congcong and Mingming is 5:3. If Congcong gives Mingming 25 books, the ratio between Congcong and Mingming will become 7:5. How many books does Congcong have now?
聪聪和明明原有课外书的本数的本数比是5：3，如果聪聪给明明25本，则聪聪和明明本数比变成7：5，现在聪聪有书多少本？
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">(5/8) - (7/12)</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">25 / (1/24)</gadget>
<output>600</output>

<gadget id="calculator">600 * (7/12)</gadget>
<output>350</output>

<result>350</result>