The distance between A and B cities is 240 kilometers. A car originally planned to drive from city A to city B in 6 hours. When the car traveled half of the distance, it stopped for 30 minutes on the way. In order to arrive at the original time, the remaining distance of the car How many kilometers per hour does the speed increase?
ab两城相距240千米，一辆汽车原定6小时从a城开往b城，汽车行驶了一半路程时，因故在途中停留30分钟，为了按原定时间到达，剩下路程汽车的速度每小时要加快多少千米？
<gadget id="calculator">240 / 2</gadget>
<output>120</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 - 0.5</gadget>
<output>2.5</output>

<gadget id="calculator">120 / 2.5</gadget>
<output>48</output>

<gadget id="calculator">240 / 6</gadget>
<output>40</output>

<gadget id="calculator">48 - 40</gadget>
<output>8</output>

<result>8</result>