Car A and Car B are traveling towards each other from two places at the same time. The speed of car A is 60 kilometers per hour, and the speed of car B is 40 kilometers per hour. When the two cars meet, car A exceeds the midpoint by 30 kilometers. How many kilometers is the road between the earth?
甲、乙两车同时从两地相向而行，甲车的速度是每小时60千米，乙车的速度是每小时40千米，两车相遇时，甲车超过中点30千米，两地间的公路长多少千米？
<gadget id="calculator">60 + 40</gadget>
<output>100</output>

<gadget id="calculator">60 - 40</gadget>
<output>20</output>

<gadget id="calculator">2 / 20</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">30 * (1/10)</gadget>
<output>3</output>

<gadget id="calculator">100 * 3</gadget>
<output>300</output>

<result>300</result>