Two people, A and B, are running a race on a 100-meter long track. If they start from the starting point at the same time, they both run to the finish line at an even speed. When A runs 80 meters, B is 10 meters behind A; when A reaches the finish line How many meters away is B from the end point?
甲、乙二人在100米长的跑道上赛跑，如果他们同时从起点出发，都以均匀的速度跑向终点，当甲跑完80米时，乙在甲的身后10米；当甲到达终点时，乙距离终点还有多少米？
<gadget id="calculator">80 - 10</gadget>
<output>70</output>

<gadget id="calculator">70 / 80</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">100 * (7/8)</gadget>
<output>175/2 = around 87.5</output>

<gadget id="calculator">100 - (175/2)</gadget>
<output>25/2 = around 12.5</output>

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