Wang Hua finished reading a 115-page book in 5 days. At this rate, how many days would it take to read a 207-page book? (Solve using ratio method)
王华5天看完一本115页的书，照这样的速度，要看207页的一本书，需要多少天？(用比例方法解答)
<gadget id="calculator">115 / 5</gadget>
<output>23</output>

<gadget id="calculator">207 / 23</gadget>
<output>9</output>

<result>9</result>