Beibei read a literary book, read 25 pages a day for the first 9 days, then read 10 pages more than the day before, and finished reading it in 3 days. How many pages does Beibei read on average every day?
贝贝读一本文艺书，前9天每天看25页，以后每天比前一天多看10页，又经过3天读完．贝贝平均每天看多少页？
<gadget id="calculator">25 * 9</gadget>
<output>225</output>

<gadget id="calculator">225 + 25 + 10 + 25 + 20 + 25 + 30</gadget>
<output>360</output>

<gadget id="calculator">9 + 3</gadget>
<output>12</output>

<gadget id="calculator">360 / 12</gadget>
<output>30</output>

<result>30</result>