Shengli Township plans to build a 15-kilometer road. In the first month, 2/5 of the total length was built, and in the second month, 30% of the total length was repaired. How many kilometers are left to be repaired?
胜利乡计划修一条15千米的公路，第一个月修了全长的(2/5)，第二个月修了全长的30%，还剩多少千米没有修？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (2/5) - (3/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">15 * (3/10)</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>