The car travels 75 kilometers per hour and the truck travels 60 kilometers per hour. 1.5 hours after the truck departs from A, the bus departs from A and travels in the same direction. How long does it take for the bus to catch up with the truck?
汽车每小时行75千米，货车每小时行60千米．货车从甲地出发1.5小时后，客车从甲地出发，同向而行，客车出发多少时间可以追上货车？
<gadget id="calculator">75 - 60</gadget>
<output>15</output>

<gadget id="calculator">1.5 / 15</gadget>
<output>0.1</output>

<gadget id="calculator">60 * 0.1</gadget>
<output>6</output>

<result>6</result>