Chen Hong travels between home and the bookstore, traveling 12 kilometers per hour by bicycle, and 30 kilometers per hour by bus when returning. It took 1.4 hours on the way back and forth. How many kilometers are there between A and B?
陈红往返家与书店，去时乘自行车每小时行12千米，返回时乘公交车每小时行30千米．往返路上共用了1.4小时，甲乙两地相距多少千米？
<gadget id="calculator">12 * 1</gadget>
<output>12</output>

<result>12</result>