The bookstore bought a batch of books yesterday, sold 40% of the books this morning, and sold 35% of the books in the afternoon. A total of 750 books were sold in one day. How many books are there in this batch?
书店昨天进了一批书，今天上午卖出了这批书的40%，下午卖出了这批书的35%，一天共卖了750册，这批书共有多少册？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">(2/5) + (7/20)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">750 / (3/4)</gadget>
<output>1_000</output>

<result>1_000</result>