Worker Xiao Wang completes a batch of parts within a certain period of time. He makes 20 parts every day for the first 4 days, and then makes 15 more parts every day for another 6 days.
工人小王在一定时间内完成一批零件，前4天每天做20个零件，后来每天多做15个零件，又做了6天，正好做完，小王平均每天做多少个零件．
<gadget id="calculator">4 * 20</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>