A and B are running a 50-meter race. When A reaches the finish line, B is 10 meters behind. The second time they race again at the same speed as the first time. end.
甲和乙进行50米赛跑，当甲到达终点时，乙落后10米，第二次两人分别按第一次的速度再赛，如果甲退到起跑线多少米开始跑，两人将会同时到达终点．
<gadget id="calculator">50 - 10</gadget>
<output>40</output>

<gadget id="calculator">50 / 40</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">50 * (5/4)</gadget>
<output>125/2 = around 62.5</output>

<gadget id="calculator">(125/2) - 50</gadget>
<output>25/2 = around 12.5</output>

<result>25/2 = around 12.5</result>