A certain brand of skirts can earn 300 yuan for each sale. After selling (3/5) of the inventory, it is decided to sell the remaining inventory at a 60% profit because of the season change. After all are sold out, the store has made a total profit of 91,200 yuan from this brand of skirts. How many sets of this kind of skirts are sold?
某品牌裙子，每卖出一条可赚300元，当卖了存货的(3/5)后，因为换季原因，决定将余下的存货让利60%出售．全部卖完后，该专卖店这种品牌裙子共获利91200元，求这种裙子卖掉多少套？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) * 300</gadget>
<output>180</output>

<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) * 300 * (3/5)</gadget>
<output>108</output>

<gadget id="calculator">300 * (3/5)</gadget>
<output>180</output>

<gadget id="calculator">108 - 180 - 180</gadget>
<output>-252</output>

<gadget id="calculator">180 + 300 + (-252)</gadget>
<output>228</output>

<gadget id="calculator">91_200 / 228</gadget>
<output>400</output>

<result>400</result>