The road repair team repaired a road. On the first day, the full length (1/2) was repaired by 20 meters. On the second day, the remaining (1/2) was repaired by 15 meters. On the third day, 50 meters were repaired, and there were still 30 meters left. Not repaired, how many meters is the total length of this road?
修路队修一条公路，第一天修了全长的(1/2)多20米，第二天修了余下的(1/2)少15米，第三天修了50米，还剩下30米未修，这条路全长是多少米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">20 * (1/2)</gadget>
<output>10</output>

<gadget id="calculator">30 - 10 - 15</gadget>
<output>5</output>

<gadget id="calculator">20 + 50 + 5</gadget>
<output>75</output>

<gadget id="calculator">(1/2) * (1/2)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/2) - (1/2)</gadget>
<output>0</output>

<gadget id="calculator">(1/4) + 0</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">75 / (1/4)</gadget>
<output>300</output>

<result>300</result>