A 7,800-meter-long road. 600 meters have been repaired, and the rest will take 30 days to complete. How many meters will be repaired on average per day?
修长7800米的公路．已经修了600米，剩下的要30天完成，剩下的平均每天要修多少米．
<gadget id="calculator">7_800 - 600</gadget>
<output>7_200</output>

<gadget id="calculator">7_200 / 30</gadget>
<output>240</output>

<result>240</result>