Xiaoliang reads a book. He reads an average of 5 pages per day in the first 3 days, and 20 pages in the next 4 days. How many pages per day on average?
小亮读一本书，前3天平均每天看5页，后4天看了20页，平均每天看多少页？
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">15 + 20</gadget>
<output>35</output>

<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">35 / 7</gadget>
<output>5</output>

<result>5</result>