Cars A and B are traveling toward each other at the same time from places A and B. When they meet, the distance ratio between cars A and B is 7:3. After the meeting, the two cars return along the original road at the same speed. When A is still far from A, when A At 20% of the distance traveled, B is 12 kilometers away from B, find the distance to AB.
甲乙两车同时从A、B两地同时相向而行，相遇时甲乙两车的路程比是7：3，相遇后两车沿原路以原速返回，当甲距A地还有相遇时甲所行路程的20%时，乙距B地12千米，求AB距离．
<gadget id="calculator">7 + 3</gadget>
<output>10</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/10) * (1/5)</gadget>
<output>3/50 = around 0.06</output>

<gadget id="calculator">12 / (3/50)</gadget>
<output>200</output>

<result>200</result>