The railway line from Beijing to Shanghai is 660 kilometers long. A train departs from Shanghai and travels 48 kilometers per hour; another train departs from Beijing and travels 72 kilometers per hour. Two trains leave at the same time, going towards each other, when will they meet? (Use the equation to solve) How many kilometers did the train from Shanghai travel when they met?
北京到上海的铁路线长660千米．一列火车从上海开出，每时行驶48千米；另一列火车从北京开出，每时行72千米．两列火车同时开出，相向而行，经过几时相遇？(用方程解)相遇时从上海开出的火车行驶多少千米？
<gadget id="calculator">48 + 72</gadget>
<output>120</output>

<gadget id="calculator">660 / 120</gadget>
<output>11/2 = around 5.5</output>

<gadget id="calculator">(11/2) * 48</gadget>
<output>264</output>

<result>264</result>