A road construction team builds a road. The ratio of the completed length to the total length is 1:3, and (1/2) of this road can be completed by repairing another 15 kilometers. What is the total length of this road in kilometers?
某修路队修一条公路，已经完成的长度与总长度的比是1：3，再修15千米就可完成这条公路的(1/2)，这条公路全长是多少千米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/2) - (1/3)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">15 / (1/6)</gadget>
<output>90</output>

<result>90</result>