A story book has 75 pages. Xiao Ming read 40% of the book on the first day and 20 pages on the second day. From which page should he start reading on the third day?
一本故事书75页，小明第一天读了全书40%，第二天读了20页，第三天应从第几页开始读？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">75 * (2/5)</gadget>
<output>30</output>

<gadget id="calculator">30 + 20 + 1</gadget>
<output>51</output>

<result>51</result>