The store shipped a batch of bicycles, and they were all sold out in three days. (1/3) of the total number was sold on the first day, 72 were sold on the second day, and (2/5) of the previous two days were sold on the third day. How many cars did you sell on the first day?
商店运来一批自行车，三天全部卖完．第一天卖出总数的(1/3)，第二天卖出72辆，第三天卖出的是前两天的(2/5)．第一天卖出多少辆？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">72 * (2/5)</gadget>
<output>144/5 = around 28.8</output>

<gadget id="calculator">72 + (144/5)</gadget>
<output>504/5 = around 100.8</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) * (2/5)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">1 - (1/3) - (2/15)</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">(504/5) / (8/15)</gadget>
<output>189</output>

<gadget id="calculator">189 * (1/3)</gadget>
<output>63</output>

<result>63</result>