Xiao Ming was doing an exercise book. He originally planned to finish it in 30 days. After doing it for 4 days as planned, he did 2 more questions every day than originally planned. After doing this for 10 days, he did 2 more questions every day. The result was exactly 5 days ahead of schedule. Finished all exercises. How many exercises are there in this book?
小明做一本习题，原计划30天完成，按计划做了4天后，他每天比原计划多做2道题，这样做了10天后，他每天又多做2道题目，结果恰好提前5天做完了全部习题．这本书中共有多少道习题．
<gadget id="calculator">11 * 4</gadget>
<output>44</output>

<gadget id="calculator">20 + 44</gadget>
<output>64</output>

<gadget id="calculator">64 / 5</gadget>
<output>64/5 = around 12.8</output>

<gadget id="calculator">(64/5) * 30</gadget>
<output>384</output>

<result>384</result>