The road construction team builds a road. The ratio of the length of the repaired to the length of the unrepaired is 2:3. After repairing another 50 kilometers, it just reaches the midpoint. How many kilometers is the total length of this road?
修路队修一条路，已修长度和未修长度的比是2：3，再修50千米刚好到达中点，这条路全长多少千米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">50 / (1/10)</gadget>
<output>500</output>

<result>500</result>