Lin Lin's home is in the mountains. He has to walk 20 minutes on the flat road and 30 minutes on the mountain road to go to school every day. He can walk 45 meters per minute on the flat road and 38 meters per minute on the mountain road. How many meters does he have to walk from home to school?
林林的家在山区．他每天上学要走20分钟的平路和30分钟的山路，在平路上他每分钟能走45米，在山路上每分钟走38米．他从家到学校要走多少米？
<gadget id="calculator">45 * 20</gadget>
<output>900</output>

<gadget id="calculator">38 * 30</gadget>
<output>1_140</output>

<gadget id="calculator">900 + 1_140</gadget>
<output>2_040</output>

<result>2_040</result>