When building a road, when it reaches the full length (3/8), there is still 30 meters away from the midpoint of the road. How long is the road in meters?
修一条公路，当修到全长的(3/8)处时，离这条公路的中点还有30米，这一条路全长多少米？
<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">30 / (1/8)</gadget>
<output>240</output>

<result>240</result>