A train of passenger cars and a train of freight trains travel backwards from the same location. When the passenger train travels at 6 o'clock and the truck at 7 o'clock, the distance between the two vehicles is 699 km. The passenger train travels 6 km longer than the freight train per hour. How many kilometers per hour does the passenger train travel?
一列客车和一列货车从同一地点向背而行，当客车行驶6时，货车行驶7时，两车相距699千米，客车每时比货车多行6千米，求客车每时行多少千米？
<gadget id="calculator">7 * 6</gadget>
<output>42</output>

<gadget id="calculator">42 + 699</gadget>
<output>741</output>

<gadget id="calculator">6 + 7</gadget>
<output>13</output>

<gadget id="calculator">741 / 13</gadget>
<output>57</output>

<result>57</result>