If a certain type of trousers in a store is marked up with a 50% increase in the cost price, and then sold at a 20% discount, and the result is a profit of 10 yuan per pair of trousers, what is the cost of the trousers?
一家商店某种裤子按成本价提高50%后标价，又以八折优惠卖出，结果每条裤子获利10元，则这条裤子的成本是多少．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * (4/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) - 1</gadget>
<output>-3/5 = around -0.6</output>

<gadget id="calculator">(4/5) + (-3/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">10 / (1/5)</gadget>
<output>50</output>

<result>50</result>