It takes 4 hours for a car to travel a road at a constant speed. If the speed of the car is reduced by one-third, how long will it take to complete the road?
汽车以等速要4小时驶完一条公路．若把汽车的速度减慢三分之一，要多久才能驶完该公路﹖
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">4 / (2/3)</gadget>
<output>6</output>

<result>6</result>