A story book has 150 pages, and after 5 days of reading, there are still 85 pages left. How many pages are you reading on average per day? (comprehensive calculation)
一本故事书150页，看了5天后还剩85页，平均每天看了多少页？(用综合式计算)
<gadget id="calculator">150 - 85</gadget>
<output>65</output>

<gadget id="calculator">65 / 5</gadget>
<output>13</output>

<result>13</result>