The People's Liberation Army will start from the garrison to the disaster area to perform disaster relief tasks. On a map with a scale of 1:50000, the distance between the garrison and the destination is 40 centimeters. It is required to arrive within 2 hours. On average, how many kilometers do you have to march per hour?
解放军要从驻地出发奔赴灾区执行救灾任务，在一幅比例尺是1：50000的地图上，量得驻地与目的地的距离是40厘米．要求在2小时内到达，平均每小时要行军多少千米？
<gadget id="calculator">1 / 50_000</gadget>
<output>1/50_000 = around 0.00002</output>

<gadget id="calculator">40 / (1/50_000) / 100_000 / 2</gadget>
<output>10</output>

<result>10</result>