To build a road with a length of 13.5 kilometers, an average of 0.2 kilometers per day in the first 15 days, and 0.35 kilometers per day for the rest, how many days will it take to complete the repair?
修一条长13.5千米的公路，前15天平均每天修0.2千米，剩下的每天修0.35千米，还要几天修完？
<gadget id="calculator">0.2 * 15</gadget>
<output>3</output>

<gadget id="calculator">13.5 - 3</gadget>
<output>10.5</output>

<gadget id="calculator">10.5 / 0.35</gadget>
<output>30</output>

<result>30</result>