Two bosses, A and B, respectively buy a fashion at the same price, and B buys more sets than A (1/6), and then A and B sell at a price of 80% and 60% profit margins respectively. After both of them are sold out, A still gets a part of the profit more than B, and this part of the profit just allows him to buy another 9 sets of this fashion, so how many sets of this fashion did B buy?
甲、乙两位老板分别以同样的价格购进一种时装，乙购进的套数比甲多(1/6)，然后甲、乙分别按获得80%和60%的利润率率定价出售，两人都售完后，甲仍比乙多获得一部分利润，这部分利润又恰好能让他再购进这种时装9套，则乙原来购进这种时装多少套？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">6 * (4/5)</gadget>
<output>24/5 = around 4.8</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">6 * (1/6)</gadget>
<output>1</output>

<gadget id="calculator">6 + 1</gadget>
<output>7</output>

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

<gadget id="calculator">7 * (3/5)</gadget>
<output>21/5 = around 4.2</output>

<gadget id="calculator">(24/5) - (21/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">9 / (3/5)</gadget>
<output>15</output>

<gadget id="calculator">15 * 7</gadget>
<output>105</output>

<result>105</result>