Cars A and B are traveling towards each other from places A and B at the same time. Car A travels 60 km per hour, and car B travels 75 km per hour. When the two cars meet, they are 30 km away from the midpoint. How many kilometers are there between A and B?
甲、乙两车同时从A、B两地相向而行，甲车每小时行60km，乙车每小时行75km，两车相遇时距中点30km，A、B两地相距多少km？
<gadget id="calculator">60 + 75</gadget>
<output>135</output>

<gadget id="calculator">75 - 60</gadget>
<output>15</output>

<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">30 * (2/15)</gadget>
<output>4</output>

<gadget id="calculator">135 * 4</gadget>
<output>540</output>

<result>540</result>