A bus and a car depart from City A to City B at the same time. After 4 hours, the car has arrived in City B, and the bus is still 80 kilometers away from City B. It is known that the speed of the car is 70 km/h, how long does it take for the bus to reach City B?
一辆客车和一辆小轿车同时从甲城出发到乙城，经过4小时，小轿车已到达乙城，客车距离乙城还有80千米．已知小轿车的速度是70千米/时，客车还有多长时间到达乙城？
<gadget id="calculator">80 / 4</gadget>
<output>20</output>

<gadget id="calculator">70 - 20</gadget>
<output>50</output>

<gadget id="calculator">4 / 50</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">70 * (2/25)</gadget>
<output>28/5 = around 5.6</output>

<gadget id="calculator">(28/5) - 4</gadget>
<output>8/5 = around 1.6</output>

<result>8/5 = around 1.6</result>