Wang Xiaoli read a 750-page book, and she read 150 pages in the first 3 days. According to this calculation, how many days will it take for her to finish reading this book? (Solve using ratio method)
王小丽读一本750页书，前3天读了150页，照这样计算，她读完这本书还需要多少天？(用比例方法解答)
<gadget id="calculator">750 - 150</gadget>
<output>600</output>

<gadget id="calculator">150 / 3</gadget>
<output>50</output>

<gadget id="calculator">600 / 50</gadget>
<output>12</output>

<result>12</result>