The distance between the two cities is 550 kilometers. A passenger car and a freight train leave from the two cities at the same time. The passenger car travels 55 kilometers per hour. The speed of the freight car is that of the passenger car (9/11). How many hours later will the two cars meet?
两城相距550千米，一列客车和一列货车同时从两个城市相对开出，客车每小时行55千米，货车的速度是客车的(9/11)，几小时后两车相遇？
<gadget id="calculator">9 / 11</gadget>
<output>9/11 = around 0.818182</output>

<gadget id="calculator">55 * (9/11)</gadget>
<output>45</output>

<gadget id="calculator">55 + 45</gadget>
<output>100</output>

<gadget id="calculator">550 / 100</gadget>
<output>11/2 = around 5.5</output>

<result>11/2 = around 5.5</result>