A car starts from point A to point B, which is 420 kilometers away. The speed of the first 120 kilometers is 40 km/h, but in order to hurry, the remaining distance needs to be driven at a speed of 60 km/h. How many hours does it take for this car to arrive at B from A?
一辆汽车从甲地出发到距离420千米的乙地，前120千米的路程的速度为40千米/时，但为了赶路，剩下的路程需以60千米/时的速度行驶，这辆汽车从甲地出发几小时能到达乙地？
<gadget id="calculator">120 / 40</gadget>
<output>3</output>

<gadget id="calculator">420 - 120</gadget>
<output>300</output>

<gadget id="calculator">300 / 60</gadget>
<output>5</output>

<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<result>8</result>