Two road construction teams, A and B, work together to build a road. A builds 3.2 kilometers a day, and B builds 4 kilometers a day. It takes 15 days. How long is this road in kilometers?
甲、乙两个修路队合修一条公路，甲每天修3.2千米，乙每天修4千米，共用了15天．这条公路全长多少千米？
<gadget id="calculator">3.2 + 4</gadget>
<output>7.2</output>

<gadget id="calculator">7.2 * 15</gadget>
<output>108</output>

<result>108</result>