The unit price of the jacket is twice that of the trousers, and the price of 3 sets of clothes is 360 yuan. How much is the price of each jacket? Which quantity should be set as x? Why?
上衣的单价是裤子的2倍，3套衣服的价格是360元，每件上衣的价钱是多少？要设哪一个量为x呢？为什么？
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">360 / 3 / 3</gadget>
<output>40</output>

<gadget id="calculator">40 * 2</gadget>
<output>80</output>

<result>80</result>