It takes 7 hours for a truck to go from place A to place B, and 9 hours for a passenger car to go from place B to place A. The two cars leave opposite to each other at the same time. The truck stops for 2 hours for some reason. 30 kilometers more, how many kilometers is the distance between A and B?
一辆货车从甲地到乙地需7小时，一辆客车从乙地到甲地需9小时，两车同时从两地相对开出，途中货车因故停车2小时，相遇时，客车比货车多行了30千米，甲乙相距多少千米？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">49 / 16</gadget>
<output>49/16 = around 3.0625</output>

<gadget id="calculator">(1/7) * (49/16)</gadget>
<output>7/16 = around 0.4375</output>

<gadget id="calculator">1 - (7/16)</gadget>
<output>9/16 = around 0.5625</output>

<gadget id="calculator">(9/16) - (7/16)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">30 / (1/8)</gadget>
<output>240</output>

<result>240</result>