If a typist types a manuscript, if he types 20 pages a day, he can finish typing in 15 days. If you want to finish typing 5 days in advance, how many pages should you type every day? (answer with ratio)
一位打字员打一本书稿，如果每天打20页，15天可以打完．若要提前5天打完，每天应打多少页？(用比例解答)
<gadget id="calculator">20 * 15</gadget>
<output>300</output>

<gadget id="calculator">15 - 5</gadget>
<output>10</output>

<gadget id="calculator">300 / 10</gadget>
<output>30</output>

<result>30</result>