Mingming finished reading a book in 10 days. He read 25 pages a day for the first 6 days, and 40 pages a day for the next 4 days. How many pages does he read on average every day?
明明用10天时间读完一本书，他前6天每天读25页，后4天每天读40页，明明平均每天读多少页．
<gadget id="calculator">25 * 6</gadget>
<output>150</output>

<gadget id="calculator">40 * 4</gadget>
<output>160</output>

<gadget id="calculator">150 + 160</gadget>
<output>310</output>

<gadget id="calculator">310 / 10</gadget>
<output>31</output>

<result>31</result>