The Beijing-Yan'an railway is 1581km long, and the trains from Beijing to Yan'an run an average of 93km per hour, and have traveled 744km. At this speed, how long will it take for the train to reach Yan'an?
北京至延安铁路长1581km，由北京开往延安的列车平均每时行93km，已经行了744km．照这样的速度，列车还要多少时间才能到达延安？
<gadget id="calculator">1_581 - 744</gadget>
<output>837</output>

<gadget id="calculator">837 / 93</gadget>
<output>9</output>

<result>9</result>