The shop brought in a batch of leather shoes, sold (1/3) of the total number on the first day, and sold (3/5) of the first day on the second day, leaving 280 pairs. How many pairs of leather shoes did the shop ship in total? ?
商店运进一批皮鞋，第一天卖出了总数的(1/3)，第二天卖出了第一天的(3/5)，还剩下280双，商店共运进皮鞋多少双？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(1/3) * (3/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/3) - (1/5)</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">280 / (7/15)</gadget>
<output>600</output>

<result>600</result>