There is a batch of eggs in the store, which sold (1/4) of the total on the first day and (2/5) of the total on the second day. A total of 39 boxes were sold in the two days. How many boxes are there in this batch of eggs?
商店里有一批鸡蛋，第一天卖出总数的(1/4)，第二天卖出总数的(2/5)，两天一共卖出39箱，这批鸡蛋共有多少箱？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/4) + (2/5)</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">39 / (13/20)</gadget>
<output>60</output>

<result>60</result>