The distance between A and B is 150 km. Two trains travel from point A to point B at the same time. The express train travels 60 kilometers per hour. The slow train travels 48 kilometers per hour. When the express train arrives at point B, how many kilometers away is the slow train from point B?
A、B两地相距150千米．两列火车同时从A地开往B地．快车每小时行60千米．慢车每小时行48千米．当快车到达B地时，慢车离B地还有多少千米．
<gadget id="calculator">150 / 60</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">48 * (5/2)</gadget>
<output>120</output>

<gadget id="calculator">150 - 120</gadget>
<output>30</output>

<result>30</result>