Uncle Li rode his bicycle from home to Hengxi for errands. He started from home by bicycle and completed half of the distance in 30 minutes. At this time, he increased his speed and traveled 50 meters more per minute than before. After another 20 minutes of riding, he knew from the mileage sign on the roadside that he had to ride another 2 kilometers to get to Hengxi, and asked for the total distance between Uncle Li's house and Hengxi.
李叔叔从家骑车去横溪办事．他从家里骑车出发，用30分钟时间行完了一半路程，这时，他加快了速度，每分钟比原来多行50米．又骑了20分钟后，他从路旁的里程标志牌上知道，必须再骑2千米才能赶到横溪，求李叔叔家到横溪之间的总路程．
<gadget id="calculator">50 * 20</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 + 2_000</gadget>
<output>3_000</output>

<gadget id="calculator">30 - 20</gadget>
<output>10</output>

<gadget id="calculator">3_000 / 10</gadget>
<output>300</output>

<gadget id="calculator">2 / 1_000</gadget>
<output>1/500 = around 0.002</output>

<gadget id="calculator">30 * 300 * (1/500)</gadget>
<output>18</output>

<result>18</result>