The road construction team builds a road, and when it reaches the full length (3/8), there is still 15 kilometers away from the midpoint. How many kilometers is this road?
修路队修一条公路，当修到全长的(3/8)时，离中点还有15千米．这条公路长多少千米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(1/2) - (3/8)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">15 / (1/8)</gadget>
<output>120</output>

<result>120</result>