Bookstores sold 1,600 books in the first quarter, which was 3/5 less than in the second quarter. How many books were sold in the second quarter?
书店第一季度售出图书1600本，比第二季度少(3/5)．第二季度售出图书多少本？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1_600 / (2/5)</gadget>
<output>4_000</output>

<result>4_000</result>