Xiaohong reads a story book, reads 20 pages a day, and finishes it in 15 days. If she reads 5 more pages a day, how many days can she finish it? (Solve with ratio)
小红读一本故事书，每天读20页，15天读完，如果每天多读5页，几天可读完？(用比例解)
<gadget id="calculator">20 * 15</gadget>
<output>300</output>

<gadget id="calculator">20 + 5</gadget>
<output>25</output>

<gadget id="calculator">300 / 25</gadget>
<output>12</output>

<result>12</result>