120-kilometer high-speed highway was repaired. 20% of the total length was repaired in the first week, and 40% of the total length was repaired in the second week. How many kilometers were repaired in total?
修一段120千米长的高速公里，第一周修了全长的20%，第二周修了全长的40%，一共修了多少千米？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/5) + (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">120 * (3/5)</gadget>
<output>72</output>

<result>72</result>