A road has been built for 120 meters, and it will be repaired again (1/5). At this time, the ratio of the repaired part to the total length is 1:3. How many meters is the total length of this road?
一条路已经修了120米，再修(1/5)，这时已修的和全长的比是1：3，这条路全长多少米？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/3) - (1/5)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">120 / (2/15)</gadget>
<output>900</output>

<result>900</result>