The total length from Beijing to Shanghai is 1,300 kilometers. The car started at 3:00 pm and traveled 780 kilometers at 9:00 pm. At this speed, how many hours will it take to reach Shanghai?
北京到上海共长1300千米，汽车从下午3：00出发，到晚上9：00行驶了780千米，照这样的速度，再需要几小时就能到达上海？
<gadget id="calculator">1_300 - 780</gadget>
<output>520</output>

<gadget id="calculator">780 / 6</gadget>
<output>130</output>

<gadget id="calculator">520 / 130</gadget>
<output>4</output>

<result>4</result>