A and B go from A to B at the same time, A travels 12 kilometers per hour, B travels 9 kilometers per hour, A travels to 18 kilometers and then goes back to pick up things, so they arrive at B 1 hour later than B , How many kilometers is the distance between A and B?
甲、乙二人同时从A地去B地，甲每小时行12千米，乙每小时行9千米，甲行至18千米处又回去取东西，因此比乙迟1小时到达B地，A、B两地相距多少千米？
<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<gadget id="calculator">36 - 12</gadget>
<output>24</output>

<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<gadget id="calculator">24 / 3</gadget>
<output>8</output>

<gadget id="calculator">8 * 9</gadget>
<output>72</output>

<result>72</result>