To build a road, the full length (3/8) was built on the first day, and the full length (2/8) was built on the second day. A total of 250 kilometers was built in two days. How long is this road?
修一条公路，第一天修了全长的(3/8)，第二天修了全长的在(2/8)，两天共修250千米，这条路有多长？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(3/8) + (1/4)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">250 / (5/8)</gadget>
<output>400</output>

<result>400</result>