In the 500-meter race. When A reaches the finish line, he is 20 meters ahead of B and 80 meters ahead of C. When B reaches the finish line, how many meters is C away from the finish line?
在500米赛跑中．当甲到终点时，超过乙20米，超过丙80米，当乙到终点时，丙离终点还有多少米？
<gadget id="calculator">500 - 20</gadget>
<output>480</output>

<gadget id="calculator">500 - 80</gadget>
<output>420</output>

<gadget id="calculator">480 / 420</gadget>
<output>8/7 = around 1.142857</output>

<gadget id="calculator">1 / (8/7)</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">500 * (7/8)</gadget>
<output>875/2 = around 437.5</output>

<gadget id="calculator">500 - (875/2)</gadget>
<output>125/2 = around 62.5</output>

<result>125/2 = around 62.5</result>