Lan Lan reads a story book, 20 pages a day for the first 4 days, then speeds up and reads 15 more pages a day than before. After another 6 days, she just finishes reading the book. How many pages does he read on average every day?
兰兰读一本故事书，前4天每天读20页，后来加快速度，每天比原来的多读15页，这样又经过6天正好读完这本书，他平均每天读了多少页？
<gadget id="calculator">20 * 4</gadget>
<output>80</output>

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

<gadget id="calculator">35 * 6</gadget>
<output>210</output>

<gadget id="calculator">80 + 210</gadget>
<output>290</output>

<gadget id="calculator">4 + 6</gadget>
<output>10</output>

<gadget id="calculator">290 / 10</gadget>
<output>29</output>

<result>29</result>